diff --git a/HACKING.md b/HACKING.md
new file mode 100644
index 0000000..ad488b6
--- /dev/null
+++ b/HACKING.md
@@ -0,0 +1,30 @@
+# Important notes on the code
+
+## Log messages
+
+### Messages
+
+- Keep your message in common format: `<problem>: <problematic value/description>`
+- If you have to write text, single quote values in your sentence.
+
+### Levels
+
+For logging, there are printf-like macros `LOG_(E|C|W|M|I|D)`.
+
+- `LOG_E` (ERROR):
+    - All messages, which lead to immediate abort and are caused by a programming error. The program needs patching and the error is not user recoverable.
+    - e.g.: Switching over an enum, `LOG_E` would go into the default case.
+- `LOG_C` (CRITICAL):
+    - The program cannot continue to work. It is used in the wrong manner or some outer conditions are not met.
+    - e.g.: `-config` parameter value is unreadable file
+- `LOG_W` (WARNING):
+    - Something is not in shape, but it's recoverable.
+    - e.g.: A value is not parsable in the config file, which will default.
+- `LOG_M` (MESSAGE):
+    - Important info, which informs about the state.
+    - e.g.: An empty notification does get removed immediately.
+- `LOG_I` (INFO):
+    - Mostly unneccessary info, but important to debug (as the user) some use cases.
+    - e.g.: print the notification contents after arriving
+- `LOG_D` (DEBUG):
+    - Only important during development or tracing some bugs (as the developer).
diff --git a/docs/dunst.pod b/docs/dunst.pod
index 0973fa8..d2c7a0b 100644
--- a/docs/dunst.pod
+++ b/docs/dunst.pod
@@ -444,6 +444,12 @@ WM_CLASS). There should be no need to modify this setting for regular use.
 Display a notification on startup. This is usually used for debugging and there
 shouldn't be any need to use this option.
 
+=item B<verbosity> (values: 'crit', 'warn', 'mesg', 'info', 'debug' default 'mesg')
+
+Do not display log messages, which have lower precedence than specified
+verbosity. This won't affect printing notifications on the terminal. Use
+the '-print' option for this.
+
 =item B<force_xinerama> (values: [true/false], default: false)
 
 Use the Xinerama extension instead of RandR for multi-monitor support. This
diff --git a/dunstrc b/dunstrc
index dbe7eab..0f4c4aa 100644
--- a/dunstrc
+++ b/dunstrc
@@ -198,6 +198,15 @@
     # automatically after a crash.
     startup_notification = false
 
+    # Manage dunst's desire for talking
+    # Can be one of the following values:
+    #  crit: Critical features. Dunst aborts
+    #  warn: Only non-fatal warnings
+    #  mesg: Important Messages
+    #  info: all unimportant stuff
+    # debug: all less than unimportant stuff
+    verbosity = mesg
+
     ### Legacy
 
     # Use the Xinerama extension instead of RandR for multi-monitor support.
diff --git a/src/dbus.c b/src/dbus.c
index 049ec19..e532813 100644
--- a/src/dbus.c
+++ b/src/dbus.c
@@ -7,6 +7,7 @@
 #include <stdlib.h>
 
 #include "dunst.h"
+#include "log.h"
 #include "notification.h"
 #include "queues.h"
 #include "settings.h"
@@ -100,8 +101,9 @@ void handle_method_call(GDBusConnection *connection,
         } else if (g_strcmp0(method_name, "GetServerInformation") == 0) {
                 on_get_server_information(connection, sender, parameters, invocation);
         } else {
-                fprintf(stderr, "WARNING: sender: %s; unknown method_name: %s\n", sender,
-                       method_name);
+                LOG_M("Unknown method name: '%s' (sender: '%s').",
+                      method_name,
+                      sender);
         }
 }
 
@@ -342,14 +344,13 @@ static void on_get_server_information(GDBusConnection *connection,
 void signal_notification_closed(notification *n, enum reason reason)
 {
         if (reason < REASON_MIN || REASON_MAX < reason) {
-                fprintf(stderr, "ERROR: Closing notification with reason '%d' not supported. "
-                                "Closing it with reason '%d'.\n", reason, REASON_UNDEF);
+                LOG_W("Closing notification with reason '%d' not supported. "
+                      "Closing it with reason '%d'.", reason, REASON_UNDEF);
                 reason = REASON_UNDEF;
         }
 
         if (!dbus_conn) {
-                fprintf(stderr, "ERROR: Tried to close notification but dbus connection not set!\n");
-                return;
+                LOG_E("Unable to close notification: No DBus connection.");
         }
 
         GVariant *body = g_variant_new("(uu)", n->id, reason);
@@ -364,7 +365,7 @@ void signal_notification_closed(notification *n, enum reason reason)
                                       &err);
 
         if (err) {
-                fprintf(stderr, "Unable to close notification: %s\n", err->message);
+                LOG_W("Unable to close notification: %s", err->message);
                 g_error_free(err);
         }
 
@@ -384,7 +385,7 @@ void signal_action_invoked(notification *n, const char *identifier)
                                       &err);
 
         if (err) {
-                fprintf(stderr, "Unable to invoke action: %s\n", err->message);
+                LOG_W("Unable to invoke action: %s", err->message);
                 g_error_free(err);
         }
 }
@@ -410,8 +411,7 @@ static void on_bus_acquired(GDBusConnection *connection,
                                                             &err);
 
         if (registration_id == 0) {
-                fprintf(stderr, "Unable to register dbus connection: %s\n", err->message);
-                exit(1);
+                DIE("Unable to register dbus connection: %s", err->message);
         }
 }
 
@@ -536,14 +536,14 @@ static void on_name_lost(GDBusConnection *connection,
         if (connection) {
                 char *name = NULL;
                 int pid = dbus_get_fdn_daemon_info(connection, &name, NULL);
-                if (pid > 0)
-                        fprintf(stderr, "Cannot acquire '"FDN_NAME"': "
-                                "Name is acquired by '%s' with PID '%d'.\n", name, pid);
-                else
-                        fprintf(stderr, "Cannot acquire '"FDN_NAME"'.\n");
-
+                if (pid > 0) {
+                        DIE("Cannot acquire '"FDN_NAME"': "
+                            "Name is acquired by '%s' with PID '%d'.", name, pid);
+                } else {
+                        DIE("Cannot acquire '"FDN_NAME"'.");
+                }
         } else {
-                fprintf(stderr, "Cannot connect to DBus.\n");
+                DIE("Cannot connect to DBus.");
         }
         exit(1);
 }
@@ -568,10 +568,10 @@ static RawImage *get_raw_image_from_data_hint(GVariant *icon_data)
                 * ((image->n_channels * image->bits_per_sample + 7) / 8);
 
         if (expected_len != g_variant_get_size (data_variant)) {
-                fprintf(stderr, "Expected image data to be of length %" G_GSIZE_FORMAT
-                       " but got a " "length of %" G_GSIZE_FORMAT,
-                       expected_len,
-                       g_variant_get_size (data_variant));
+                LOG_W("Expected image data to be of length %" G_GSIZE_FORMAT
+                      " but got a length of %" G_GSIZE_FORMAT,
+                      expected_len,
+                      g_variant_get_size(data_variant));
                 g_free(image);
                 g_variant_unref(data_variant);
                 return NULL;
diff --git a/src/dunst.c b/src/dunst.c
index 38c8957..53fb2fc 100644
--- a/src/dunst.c
+++ b/src/dunst.c
@@ -13,6 +13,7 @@
 #include <stdlib.h>
 
 #include "dbus.h"
+#include "log.h"
 #include "menu.h"
 #include "notification.h"
 #include "option_parser.h"
@@ -25,10 +26,6 @@
 #define VERSION "version info needed"
 #endif
 
-#define MSG 1
-#define INFO 2
-#define DEBUG 3
-
 typedef struct _x11_source {
         GSource source;
         Display *dpy;
@@ -128,11 +125,17 @@ int dunst_main(int argc, char *argv[])
 
         cmdline_load(argc, argv);
 
+        dunst_log_init(false);
+
         if (cmdline_get_bool("-v/-version", false, "Print version")
             || cmdline_get_bool("--version", false, "Print version")) {
                 print_version();
         }
 
+        char *verbosity = cmdline_get_string("-verbosity", NULL, "Minimum level for message");
+        log_set_level_from_string(verbosity);
+        g_free(verbosity);
+
         char *cmdline_config_path;
         cmdline_config_path =
             cmdline_get_string("-conf/-config", NULL,
diff --git a/src/dunst.h b/src/dunst.h
index cdb6874..ac5cda6 100644
--- a/src/dunst.h
+++ b/src/dunst.h
@@ -9,8 +9,6 @@
 
 #include "notification.h"
 
-#define PERR(msg, errnum) printf("(%d) %s : %s\n", __LINE__, (msg), (strerror(errnum)))
-
 #define ColLast 3
 #define ColFrame 2
 #define ColFG 1
diff --git a/src/log.c b/src/log.c
new file mode 100644
index 0000000..ad777f6
--- /dev/null
+++ b/src/log.c
@@ -0,0 +1,95 @@
+/* copyright 2012 - 2013 Sascha Kruse and contributors (see LICENSE for licensing information) */
+
+#include "log.h"
+
+#include <glib.h>
+
+static GLogLevelFlags log_level = G_LOG_LEVEL_WARNING;
+
+static const char *log_level_to_string(GLogLevelFlags level)
+{
+        switch (level) {
+        case G_LOG_LEVEL_ERROR: return "ERROR";
+        case G_LOG_LEVEL_CRITICAL: return "CRITICAL";
+        case G_LOG_LEVEL_WARNING: return "WARNING";
+        case G_LOG_LEVEL_MESSAGE: return "MESSAGE";
+        case G_LOG_LEVEL_INFO: return "INFO";
+        case G_LOG_LEVEL_DEBUG: return "DEBUG";
+        default: return "UNKNOWN";
+        }
+}
+
+void log_set_level_from_string(const char *level)
+{
+        if (!level)
+                return;
+
+        if (g_ascii_strcasecmp(level, "critical") == 0)
+                log_level = G_LOG_LEVEL_CRITICAL;
+        else if (g_ascii_strcasecmp(level, "crit") == 0)
+                log_level = G_LOG_LEVEL_CRITICAL;
+        else if (g_ascii_strcasecmp(level, "warning") == 0)
+                log_level = G_LOG_LEVEL_WARNING;
+        else if (g_ascii_strcasecmp(level, "warn") == 0)
+                log_level = G_LOG_LEVEL_WARNING;
+        else if (g_ascii_strcasecmp(level, "message") == 0)
+                log_level = G_LOG_LEVEL_MESSAGE;
+        else if (g_ascii_strcasecmp(level, "mesg") == 0)
+                log_level = G_LOG_LEVEL_MESSAGE;
+        else if (g_ascii_strcasecmp(level, "info") == 0)
+                log_level = G_LOG_LEVEL_INFO;
+        else if (g_ascii_strcasecmp(level, "debug") == 0)
+                log_level = G_LOG_LEVEL_DEBUG;
+        else if (g_ascii_strcasecmp(level, "deb") == 0)
+                log_level = G_LOG_LEVEL_DEBUG;
+        else
+                LOG_W("Unknown log level: '%s'", level);
+}
+
+void log_set_level(GLogLevelFlags level)
+{
+        log_level = level;
+}
+
+/*
+ * Log handling function for GLib's logging wrapper
+ *
+ * If the gpointer is valid, do not do anything
+ */
+static void dunst_log_handler(
+                const gchar    *log_domain,
+                GLogLevelFlags  message_level,
+                const gchar    *message,
+                gpointer        testing)
+{
+        if (testing)
+                return;
+
+/* if you want to have a debug build, you want to log anything,
+ * unconditionally, without specifying debug log level again */
+#ifndef DEBUG_BUILD
+        if (log_level < message_level)
+                return;
+#endif
+        const char *log_level_str =
+                log_level_to_string(message_level & G_LOG_LEVEL_MASK);
+
+        /* Use stderr for warnings and higher */
+        if (message_level <= G_LOG_LEVEL_WARNING)
+                g_printerr("%s: %s\n", log_level_str, message);
+        else
+                g_print("%s: %s\n", log_level_str, message);
+}
+
+/*
+ * Initialise log handling. Can be called any time.
+ *
+ * If bool is %TRUE, it suppresses all logging output.
+ * Primarily used for testing
+ */
+void dunst_log_init(bool testing)
+{
+        g_log_set_default_handler(dunst_log_handler, (void*)testing);
+}
+
+/* vim: set tabstop=8 shiftwidth=8 expandtab textwidth=0: */
diff --git a/src/log.h b/src/log.h
new file mode 100644
index 0000000..3ca6e9d
--- /dev/null
+++ b/src/log.h
@@ -0,0 +1,25 @@
+/* copyright 2013 Sascha Kruse and contributors (see LICENSE for licensing information) */
+
+#include <glib.h>
+#include <stdbool.h>
+#include <stdlib.h>
+
+#ifndef DUNST_LOG_H
+#define DUNST_LOG_H
+
+#define LOG_E g_error
+#define LOG_C g_critical
+#define LOG_W g_warning
+#define LOG_M g_message
+#define LOG_I g_info
+#define LOG_D g_debug
+
+#define DIE(...) do { LOG_C(__VA_ARGS__); exit(EXIT_FAILURE); } while (0)
+
+void log_set_level(GLogLevelFlags level);
+void log_set_level_from_string(const char* level);
+
+void dunst_log_init(bool testing);
+
+#endif
+/* vim: set tabstop=8 shiftwidth=8 expandtab textwidth=0: */
diff --git a/src/markup.c b/src/markup.c
index ad4484f..4ed6585 100644
--- a/src/markup.c
+++ b/src/markup.c
@@ -7,6 +7,7 @@
 #include <string.h>
 #include <stdio.h>
 
+#include "log.h"
 #include "settings.h"
 #include "utils.h"
 
@@ -68,17 +69,15 @@ void markup_strip_a(char **str, char **urls)
 
                 // the tag is broken, ignore it
                 if (!tag1_end) {
-                        fprintf(stderr,
-                                "WARNING: Given link is broken: '%s'\n",
-                                tag1);
+                        LOG_W("Given link is broken: '%s'",
+                              tag1);
                         string_replace_at(*str, tag1-*str, strlen(tag1), "");
                         break;
                 }
                 if (tag2 && tag2 < tag1_end) {
                         int repl_len =  (tag2 - tag1) + strlen("</a>");
-                        fprintf(stderr,
-                                "WARNING: Given link is broken: '%.*s.'\n",
-                                repl_len, tag1);
+                        LOG_W("Given link is broken: '%.*s.'",
+                              repl_len, tag1);
                         string_replace_at(*str, tag1-*str, repl_len, "");
                         break;
                 }
@@ -147,7 +146,7 @@ void markup_strip_img(char **str, char **urls)
 
                 // the tag is broken, ignore it
                 if (!end) {
-                        fprintf(stderr, "WARNING: Given image is broken: '%s'\n", start);
+                        LOG_W("Given image is broken: '%s'", start);
                         string_replace_at(*str, start-*str, strlen(start), "");
                         break;
                 }
@@ -188,9 +187,8 @@ void markup_strip_img(char **str, char **urls)
                         text_src = g_strndup(src_s, src_e-src_s);
 
                 } else {
-                        fprintf(stderr,
-                                "WARNING: Given image argument is broken: '%.*s'\n",
-                                (int)(end-start), start);
+                         LOG_W("Given image argument is broken: '%.*s'",
+                               (int)(end-start), start);
                 }
 
                 // replacement text for alt
diff --git a/src/menu.c b/src/menu.c
index 4e2389d..2689839 100644
--- a/src/menu.c
+++ b/src/menu.c
@@ -14,6 +14,7 @@
 
 #include "dbus.h"
 #include "dunst.h"
+#include "log.h"
 #include "notification.h"
 #include "queues.h"
 #include "settings.h"
@@ -33,7 +34,7 @@ static int regex_init(void)
             "(\\([-[:alnum:]_\\@;/?:&=%$.+!*\x27,~#]*\\)|[-[:alnum:]_\\@;/?:&=%$+*~])+";
         int ret = regcomp(&cregex, regex, REG_EXTENDED | REG_ICASE);
         if (ret != 0) {
-                fputs("failed to compile regex", stderr);
+                LOG_W("Failed to compile regex.");
                 return 0;
         } else {
                 is_initialized = true;
@@ -139,7 +140,7 @@ void invoke_action(const char *action)
 
         char *appname_begin = strchr(action, '[');
         if (!appname_begin) {
-                printf("invalid action: %s\n", action);
+                LOG_W("Invalid action: '%s'", action);
                 return;
         }
         appname_begin++;
@@ -193,7 +194,7 @@ void dispatch_menu_result(const char *input)
 void context_menu(void)
 {
         if (settings.dmenu_cmd == NULL) {
-                fprintf(stderr, "dmenu command not set properly. Cowardly refusing to open the context menu.\n");
+                LOG_C("Unable to open dmenu: No dmenu command set.");
                 return;
         }
         char *dmenu_input = NULL;
@@ -218,12 +219,12 @@ void context_menu(void)
         int child_io[2];
         int parent_io[2];
         if (pipe(child_io) != 0) {
-                PERR("pipe()", errno);
+                LOG_W("pipe(): error in child: %s", strerror(errno));
                 g_free(dmenu_input);
                 return;
         }
         if (pipe(parent_io) != 0) {
-                PERR("pipe()", errno);
+                LOG_W("pipe(): error in parent: %s", strerror(errno));
                 g_free(dmenu_input);
                 return;
         }
@@ -234,12 +235,12 @@ void context_menu(void)
                 close(parent_io[0]);
                 close(0);
                 if (dup(child_io[0]) == -1) {
-                        PERR("dup()", errno);
+                        LOG_W("dup(): error in child: %s", strerror(errno));
                         exit(EXIT_FAILURE);
                 }
                 close(1);
                 if (dup(parent_io[1]) == -1) {
-                        PERR("dup()", errno);
+                        LOG_W("dup(): error in parent: %s", strerror(errno));
                         exit(EXIT_FAILURE);
                 }
                 execvp(settings.dmenu_cmd[0], settings.dmenu_cmd);
@@ -252,7 +253,7 @@ void context_menu(void)
                 close(parent_io[1]);
                 size_t wlen = strlen(dmenu_input);
                 if (write(child_io[1], dmenu_input, wlen) != wlen) {
-                        PERR("write()", errno);
+                        LOG_W("write(): error: %s", strerror(errno));
                 }
                 close(child_io[1]);
 
diff --git a/src/notification.c b/src/notification.c
index 13dba18..f689193 100644
--- a/src/notification.c
+++ b/src/notification.c
@@ -15,6 +15,7 @@
 
 #include "dbus.h"
 #include "dunst.h"
+#include "log.h"
 #include "markup.h"
 #include "menu.h"
 #include "queues.h"
@@ -33,6 +34,7 @@ static void notification_dmenu_string(notification *n);
  */
 void notification_print(notification *n)
 {
+        //TODO: use logging info for this
         printf("{\n");
         printf("\tappname: '%s'\n", n->appname);
         printf("\tsummary: '%s'\n", n->summary);
@@ -106,7 +108,7 @@ void notification_run_script(notification *n)
                                          urgency,
                                          (char *)NULL);
                         if (ret != 0) {
-                                PERR("Unable to run script", errno);
+                                LOG_W("Unable to run script: %s", strerror(errno));
                                 exit(EXIT_FAILURE);
                         }
                 }
@@ -416,12 +418,11 @@ static void notification_format_message(notification *n)
                                 MARKUP_NO);
                         break;
                 case '\0':
-                        fprintf(stderr, "WARNING: format_string has trailing %% character."
-                                        "To escape it use %%%%.");
+                        LOG_W("format_string has trailing %% character. "
+                              "To escape it use %%%%.");
                         break;
                 default:
-                        fprintf(stderr, "WARNING: format_string %%%c"
-                                        " is unknown\n", substr[1]);
+                        LOG_W("format_string %%%c is unknown.", substr[1]);
                         // shift substr pointer forward,
                         // as we can't interpret the format string
                         substr++;
diff --git a/src/option_parser.c b/src/option_parser.c
index 7641ccb..6573d73 100644
--- a/src/option_parser.c
+++ b/src/option_parser.c
@@ -8,6 +8,8 @@
 #include <stdlib.h>
 #include <string.h>
 
+#include "dunst.h"
+#include "log.h"
 #include "utils.h"
 
 typedef struct _entry_t {
@@ -42,7 +44,7 @@ section_t *new_section(const char *name)
 {
         for (int i = 0; i < section_count; i++) {
                 if (!strcmp(name, sections[i].name)) {
-                        die("Duplicated section in dunstrc detected.\n", -1);
+                        DIE("Duplicated section in dunstrc detected.");
                 }
         }
 
@@ -238,10 +240,7 @@ int load_ini_file(FILE *fp)
                 if (*start == '[') {
                         char *end = strchr(start + 1, ']');
                         if (!end) {
-                                fprintf(stderr,
-                                     "Warning: invalid config file at line %d\n",
-                                     line_num);
-                                fprintf(stderr, "Missing ']'\n");
+                                LOG_W("Invalid config file at line %d: Missing ']'.", line_num);
                                 continue;
                         }
 
@@ -255,10 +254,7 @@ int load_ini_file(FILE *fp)
 
                 char *equal = strchr(start + 1, '=');
                 if (!equal) {
-                        fprintf(stderr,
-                               "Warning: invalid config file at line %d\n",
-                               line_num);
-                        fprintf(stderr, "Missing '='\n");
+                        LOG_W("Invalid config file at line %d: Missing '='.", line_num);
                         continue;
                 }
 
@@ -270,10 +266,7 @@ int load_ini_file(FILE *fp)
                 if (quote) {
                         char *closing_quote = strchr(quote + 1, '"');
                         if (!closing_quote) {
-                                fprintf(stderr,
-                                     "Warning: invalid config file at line %d\n",
-                                     line_num);
-                                fprintf(stderr, "Missing '\"'\n");
+                                LOG_W("Invalid config file at line %d: Missing '\"'.", line_num);
                                 continue;
                         }
                 } else {
@@ -284,10 +277,7 @@ int load_ini_file(FILE *fp)
                 value = g_strstrip(value);
 
                 if (!current_section) {
-                        fprintf(stderr,
-                               "Warning: invalid config file at line %d\n",
-                               line_num);
-                        fprintf(stderr, "Key value pair without a section\n");
+                        LOG_W("Invalid config file at line %d: Key value pair without a section.", line_num);
                         continue;
                 }
 
@@ -348,8 +338,7 @@ static const char *cmdline_get_value(const char *key)
 
         if (idx + 1 >= cmdline_argc) {
                 /* the argument is missing */
-                fprintf(stderr, "Warning: %s, missing argument. Ignoring\n",
-                        key);
+                LOG_W("%s: Missing argument. Ignoring.", key);
                 return NULL;
         }
         return cmdline_argv[idx + 1];
diff --git a/src/queues.c b/src/queues.c
index 67953b5..94c0c7f 100644
--- a/src/queues.c
+++ b/src/queues.c
@@ -7,6 +7,7 @@
 #include <stdio.h>
 #include <string.h>
 
+#include "log.h"
 #include "notification.h"
 #include "settings.h"
 
@@ -59,7 +60,7 @@ int queues_notification_insert(notification *n)
                 if (settings.always_run_script) {
                         notification_run_script(n);
                 }
-                printf("skipping notification: %s %s\n", n->body, n->summary);
+                LOG_M("Skipping notification: '%s' '%s'", n->body, n->summary);
                 return 0;
         }
         /* Do not insert the message if it's a command */
diff --git a/src/settings.c b/src/settings.c
index 90fc321..c9264f5 100644
--- a/src/settings.c
+++ b/src/settings.c
@@ -13,6 +13,7 @@
 #include "rules.h" // put before config.h to fix missing include
 #include "config.h"
 #include "dunst.h"
+#include "log.h"
 #include "notification.h"
 #include "option_parser.h"
 #include "utils.h"
@@ -28,7 +29,7 @@ static void parse_follow_mode(const char *mode)
         else if (strcmp(mode, "none") == 0)
                 settings.f_mode = FOLLOW_NONE;
         else {
-                fprintf(stderr, "Warning: unknown follow mode: \"%s\"\n", mode);
+                LOG_W("Unknown follow mode: '%s'", mode);
                 settings.f_mode = FOLLOW_NONE;
         }
 }
@@ -42,7 +43,7 @@ static enum markup_mode parse_markup_mode(const char *mode)
         } else if (strcmp(mode, "full") == 0 || strcmp(mode, "yes") == 0) {
                 return MARKUP_FULL;
         } else {
-                fprintf(stderr, "Warning: unknown markup mode: \"%s\"\n", mode);
+                LOG_W("Unknown markup mode: '%s'", mode);
                 return MARKUP_NO;
         }
 }
@@ -60,9 +61,7 @@ static enum urgency ini_get_urgency(const char *section, const char *key, const
                 else if (strcmp(urg, "critical") == 0)
                         ret = URG_CRIT;
                 else
-                        fprintf(stderr,
-                                "unknown urgency: %s, ignoring\n",
-                                urg);
+                        LOG_W("Unknown urgency: '%s'", urg);
         }
         g_free(urg);
         return ret;
@@ -85,10 +84,7 @@ void load_settings(char *cmdline_config_path)
                 }
 
                 if(!config_file) {
-                        char *msg = g_strdup_printf(
-                                        "Cannot find config file: '%s'\n",
-                                        cmdline_config_path);
-                        die(msg, 1);
+                        DIE("Cannot find config file: '%s'", cmdline_config_path);
                 }
         }
         if (config_file == NULL) {
@@ -99,17 +95,29 @@ void load_settings(char *cmdline_config_path)
                  * (before v0.2). */
                 config_file = xdgConfigOpen("dunstrc", "r", &xdg);
                 if (config_file == NULL) {
-                        puts("no dunstrc found -> skipping\n");
+                        LOG_W("No dunstrc found.");
                         xdgWipeHandle(&xdg);
                 }
         }
 
         load_ini_file(config_file);
 #else
-        fprintf(stderr, "Warning: dunstrc parsing disabled. "
-                        "Using STATIC_CONFIG is deprecated behavior.\n");
+        LOG_M("dunstrc parsing disabled. "
+              "Using STATIC_CONFIG is deprecated behavior.");
 #endif
 
+        {
+                char *loglevel = option_get_string(
+                                "global",
+                                "verbosity", "-verbosity", NULL,
+                                "The verbosity to log (one of 'crit', 'warn', 'mesg', 'info', 'debug')"
+                        );
+
+                log_set_level_from_string(loglevel);
+
+                g_free(loglevel);
+        }
+
         settings.per_monitor_dpi = option_get_bool(
                 "experimental",
                 "per_monitor_dpi", NULL, false,
@@ -138,7 +146,8 @@ void load_settings(char *cmdline_config_path)
                         );
 
                         settings.markup = (allow_markup ? MARKUP_FULL : MARKUP_STRIP);
-                        fprintf(stderr, "Warning: 'allow_markup' is deprecated, please use 'markup' instead.\n");
+                        LOG_M("'allow_markup' is deprecated, please "
+                              "use 'markup' instead.");
                 }
 
                 char *c = option_get_string(
@@ -198,7 +207,7 @@ void load_settings(char *cmdline_config_path)
                 } else if (strcmp(c, "end") == 0) {
                         settings.ellipsize = end;
                 } else {
-                        fprintf(stderr, "Warning: unknown ellipsize value: \"%s\"\n", c);
+                        LOG_W("Unknown ellipsize value: '%s'", c);
                         settings.ellipsize = defaults.ellipsize;
                 }
                 g_free(c);
@@ -286,8 +295,7 @@ void load_settings(char *cmdline_config_path)
                         else if (strcmp(c, "right") == 0)
                                 settings.align = right;
                         else
-                                fprintf(stderr,
-                                        "Warning: unknown alignment\n");
+                                LOG_W("Unknown alignment value: '%s'", c);
                         g_free(c);
                 }
         }
@@ -389,8 +397,8 @@ void load_settings(char *cmdline_config_path)
         {
                 GError *error = NULL;
                 if (!g_shell_parse_argv(settings.dmenu, NULL, &settings.dmenu_cmd, &error)) {
-                        fprintf(stderr, "Unable to parse dmenu command: %s\n", error->message);
-                        fprintf(stderr, "dmenu functionality will be disabled.\n");
+                        LOG_W("Unable to parse dmenu command: '%s'."
+                              "dmenu functionality will be disabled.", error->message);
                         g_error_free(error);
                         settings.dmenu_cmd = NULL;
                 }
@@ -418,8 +426,7 @@ void load_settings(char *cmdline_config_path)
                         else if (strcmp(c, "off") == 0)
                                 settings.icon_position = icons_off;
                         else
-                                fprintf(stderr,
-                                        "Warning: unknown icon position: %s\n", c);
+                                LOG_W("Unknown icon position: '%s'", c);
                         g_free(c);
                 }
         }
@@ -438,7 +445,7 @@ void load_settings(char *cmdline_config_path)
                         "icon_folders", "-icon_folders", defaults.icon_path,
                         "folders to default icons (deprecated, please use 'icon_path' instead)"
                 );
-                fprintf(stderr, "Warning: 'icon_folders' is deprecated, please use 'icon_path' instead.\n");
+                LOG_M("The option 'icon_folders' is deprecated, please use 'icon_path' instead.");
         }
         // Read value and generate usage string for icon_path.
         // If icon_path is set, override icon_folder.
@@ -458,7 +465,9 @@ void load_settings(char *cmdline_config_path)
                                 "width", NULL, defaults.frame_width,
                                 "Width of frame around the window"
                         );
-                        fprintf(stderr, "Warning: The frame section is deprecated, width has been renamed to frame_width and moved to the global section.\n");
+                        LOG_M("The frame section is deprecated, width has "
+                              "been renamed to frame_width and moved to "
+                              "the global section.");
                 }
 
                 settings.frame_width = option_get_int(
@@ -474,7 +483,9 @@ void load_settings(char *cmdline_config_path)
                                 "color", NULL, defaults.frame_color,
                                 "Color of the frame around the window"
                         );
-                        fprintf(stderr, "Warning: The frame section is deprecated, color has been renamed to frame_color and moved to the global section.\n");
+                        LOG_M("The frame section is deprecated, color "
+                              "has been renamed to frame_color and moved "
+                              "to the global section.");
                 }
 
                 settings.frame_color = option_get_string(
diff --git a/src/test b/src/test
new file mode 100755
index 0000000..66605e6
Binary files /dev/null and b/src/test differ
diff --git a/src/utils.c b/src/utils.c
index eff2f78..8d2f00e 100644
--- a/src/utils.c
+++ b/src/utils.c
@@ -8,6 +8,8 @@
 #include <stdlib.h>
 #include <string.h>
 
+#include "log.h"
+
 char *string_replace_char(char needle, char replacement, char *haystack)
 {
         char *current = haystack;
@@ -134,13 +136,13 @@ gint64 string_to_time(const char *string)
         gint64 val = strtoll(string, &endptr, 10);
 
         if (errno != 0) {
-                fprintf(stderr, "ERROR: Time: '%s': %s.\n", string, strerror(errno));
+                LOG_W("Time: '%s': %s.", string, strerror(errno));
                 return 0;
         } else if (string == endptr) {
-                fprintf(stderr, "ERROR: Time: No digits found.\n");
+                LOG_W("Time: '%s': No digits found.", string);
                 return 0;
         } else if (errno != 0 && val == 0) {
-                fprintf(stderr, "ERROR: Time: '%s' unknown error.\n", string);
+                LOG_W("Time: '%s': Unknown error.", string);
                 return 0;
         } else if (errno == 0 && !*endptr) {
                 return val * G_USEC_PER_SEC;
@@ -164,10 +166,4 @@ gint64 string_to_time(const char *string)
                 return 0;
 }
 
-void die(char *text, int exit_value)
-{
-        fputs(text, stderr);
-        exit(exit_value);
-}
-
 /* vim: set tabstop=8 shiftwidth=8 expandtab textwidth=0: */
diff --git a/src/utils.h b/src/utils.h
index 18333d9..874bb49 100644
--- a/src/utils.h
+++ b/src/utils.h
@@ -21,9 +21,6 @@ char *string_append(char *a, const char *b, const char *sep);
 /* strip content between two delimiter characters (inplace) */
 void string_strip_delimited(char *str, char a, char b);
 
-/* exit with an error message */
-void die(char *msg, int exit_value);
-
 /* replace tilde and path-specific values with its equivalents */
 char *string_to_path(char *string);
 
diff --git a/src/x11/screen.c b/src/x11/screen.c
index 07a22a6..51bc230 100644
--- a/src/x11/screen.c
+++ b/src/x11/screen.c
@@ -15,6 +15,7 @@
 #include <stdlib.h>
 #include <string.h>
 
+#include "src/log.h"
 #include "src/settings.h"
 #include "x.h"
 
@@ -90,7 +91,8 @@ void randr_init()
 {
         int randr_error_base = 0;
         if (!XRRQueryExtension(xctx.dpy, &randr_event_base, &randr_error_base)) {
-                fprintf(stderr, "Could not initialize the RandR extension, falling back to single monitor mode.\n");
+                LOG_W("Could not initialize the RandR extension. "
+                      "Falling back to single monitor mode.");
                 return;
         }
         XRRQueryVersion(xctx.dpy, &randr_major_version, &randr_minor_version);
@@ -101,9 +103,10 @@ void randr_update()
 {
         if (randr_major_version < 1
             || (randr_major_version == 1 && randr_minor_version < 5)) {
-                fprintf(stderr, "Server RandR version too low (%i.%i). Falling back to single monitor mode\n",
-                                randr_major_version,
-                                randr_minor_version);
+                LOG_W("Server RandR version too low (%i.%i). "
+                      "Falling back to single monitor mode.",
+                      randr_major_version,
+                      randr_minor_version);
                 screen_update_fallback();
                 return;
         }
@@ -112,7 +115,8 @@ void randr_update()
         XRRMonitorInfo *m = XRRGetMonitors(xctx.dpy, RootWindow(xctx.dpy, DefaultScreen(xctx.dpy)), true, &n);
 
         if (n < 1) {
-                fprintf(stderr, "Get monitors reported %i monitors, falling back to single monitor mode\n", n);
+                LOG_C("Get monitors reported %i monitors. "
+                      "Falling back to single monitor mode.", n);
                 screen_update_fallback();
                 return;
         }
@@ -150,7 +154,8 @@ void xinerama_update()
         XineramaScreenInfo *info = XineramaQueryScreens(xctx.dpy, &n);
 
         if (!info) {
-                fprintf(stderr, "(Xinerama) Could not get screen info, falling back to single monitor mode\n");
+                LOG_W("Could not get xinerama screen info. "
+                      "Falling back to single monitor mode.");
                 screen_update_fallback();
                 return;
         }
@@ -326,8 +331,7 @@ static int FollowXErrorHandler(Display *display, XErrorEvent *e)
         dunst_follow_errored = true;
         char err_buf[BUFSIZ];
         XGetErrorText(display, e->error_code, err_buf, BUFSIZ);
-        fputs(err_buf, stderr);
-        fputs("\n", stderr);
+        LOG_W("%s", err_buf);
 
         return 0;
 }
diff --git a/src/x11/x.c b/src/x11/x.c
index 0f38487..2df610b 100644
--- a/src/x11/x.c
+++ b/src/x11/x.c
@@ -26,6 +26,7 @@
 
 #include "src/dbus.h"
 #include "src/dunst.h"
+#include "src/log.h"
 #include "src/markup.h"
 #include "src/notification.h"
 #include "src/queues.h"
@@ -83,7 +84,7 @@ static color_t x_string_to_color_t(const char *str)
         char *end;
         long int val = strtol(str+1, &end, 16);
         if (*end != '\0' && *(end+1) != '\0') {
-                printf("WARNING: Invalid color string: \"%s\"\n", str);
+                LOG_W("Invalid color string: '%s'", str);
         }
 
         return x_color_hex_to_double(val);
@@ -132,9 +133,7 @@ static color_t x_get_separator_color(colored_layout *cl, colored_layout *cl_next
         case AUTO:
                 return calculate_foreground_color(cl->bg);
         default:
-                printf("Unknown separator color type. Please file a Bugreport.\n");
-                return cl->fg;
-
+                LOG_E("Unknown separator color type.");
         }
 }
 
@@ -378,8 +377,7 @@ static GdkPixbuf *get_pixbuf_from_path(char *icon_path)
                         } while (*(end) != '\0');
                 }
                 if (pixbuf == NULL) {
-                        fprintf(stderr,
-                                "Could not load icon: '%s'\n", icon_path);
+                        LOG_W("Could not load icon: '%s'", icon_path);
                 }
                 if (uri_path != NULL) {
                         g_free(uri_path);
@@ -534,7 +532,7 @@ static colored_layout *r_create_layout_from_notification(cairo_t *c, notificatio
                 cl->attr = NULL;
                 pango_layout_set_text(cl->l, n->text_to_render, -1);
                 if (n->first_render) {
-                        printf("Error parsing markup: %s\n", err->message);
+                        LOG_W("Unable to parse markup: %s", err->message);
                 }
                 g_error_free(err);
         }
@@ -833,8 +831,6 @@ gboolean x_mainloop_fd_prepare(GSource *source, gint *timeout)
 {
         if (timeout)
                 *timeout = -1;
-        else
-                g_print("BUG: x_mainloop_fd_prepare: timeout == NULL\n");
         return false;
 }
 
@@ -994,9 +990,9 @@ void x_setup(void)
 
         /* initialize xctx.dc, font, keyboard, colors */
         if (!setlocale(LC_CTYPE, "") || !XSupportsLocale())
-                fputs("no locale support\n", stderr);
+                LOG_W("No locale support");
         if (!(xctx.dpy = XOpenDisplay(NULL))) {
-                die("cannot open display\n", EXIT_FAILURE);
+                DIE("Cannot open X11 display.");
         }
 
         x_shortcut_init(&settings.close_ks);
@@ -1193,7 +1189,7 @@ void x_win_show(void)
                     None,
                     None);
         if (x_shortcut_tear_down_error_handler()) {
-                fprintf(stderr, "Unable to grab mouse button(s)\n");
+                LOG_W("Unable to grab mouse button(s).");
         }
 
         XMapRaised(xctx.dpy, xctx.win);
@@ -1233,7 +1229,7 @@ KeySym x_shortcut_string_to_mask(const char *str)
         } else if (!strcmp(str, "shift")) {
                 return ShiftMask;
         } else {
-                fprintf(stderr, "Warning: Unknown Modifier: %s\n", str);
+                LOG_W("Unknown Modifier: '%s'", str);
                 return 0;
         }
 }
@@ -1246,11 +1242,11 @@ static int GrabXErrorHandler(Display *display, XErrorEvent *e)
         dunst_grab_errored = true;
         char err_buf[BUFSIZ];
         XGetErrorText(display, e->error_code, err_buf, BUFSIZ);
-        fputs(err_buf, stderr);
-        fputs("\n", stderr);
 
         if (e->error_code != BadAccess) {
-                exit(EXIT_FAILURE);
+                DIE("%s", err_buf);
+        } else {
+                LOG_W("%s", err_buf);
         }
 
         return 0;
@@ -1308,7 +1304,7 @@ int x_shortcut_grab(keyboard_shortcut *ks)
         }
 
         if (x_shortcut_tear_down_error_handler()) {
-                fprintf(stderr, "Unable to grab key \"%s\"\n", ks->str);
+                LOG_W("Unable to grab key '%s'.", ks->str);
                 ks->is_valid = false;
                 return 1;
         }
@@ -1371,8 +1367,7 @@ void x_shortcut_init(keyboard_shortcut *ks)
         }
 
         if (ks->sym == NoSymbol || ks->code == NoSymbol) {
-                fprintf(stderr, "Warning: Unknown keyboard shortcut: %s\n",
-                        ks->str);
+                LOG_W("Unknown keyboard shortcut: '%s'", ks->str);
                 ks->is_valid = false;
         } else {
                 ks->is_valid = true;
diff --git a/test/test.c b/test/test.c
index 90959a6..935bda9 100644
--- a/test/test.c
+++ b/test/test.c
@@ -1,5 +1,9 @@
 #include "greatest.h"
 
+#include <stdbool.h>
+
+#include "src/log.h"
+
 SUITE_EXTERN(suite_utils);
 SUITE_EXTERN(suite_option_parser);
 SUITE_EXTERN(suite_notification);
@@ -8,6 +12,9 @@ SUITE_EXTERN(suite_markup);
 GREATEST_MAIN_DEFS();
 
 int main(int argc, char *argv[]) {
+        // do not print out warning messages, when executing tests
+        dunst_log_init(true);
+
         GREATEST_MAIN_BEGIN();
         RUN_SUITE(suite_utils);
         RUN_SUITE(suite_option_parser);