diff --git a/eek/eek-element.c b/eek/eek-element.c
index f44361d3..a830729b 100644
--- a/eek/eek-element.c
+++ b/eek/eek-element.c
@@ -100,6 +100,7 @@ eek_element_set_property (GObject      *object,
         break;
     case PROP_LEVEL:
         eek_element_set_level (element, g_value_get_int (value));
+        break;
     default:
         G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
         break;
diff --git a/meson.build b/meson.build
index 1165b33f..5c74b5ae 100644
--- a/meson.build
+++ b/meson.build
@@ -11,6 +11,16 @@ project(
     ]
 )
 
+add_project_arguments(
+  [
+    '-Werror=implicit-function-declaration',
+    '-Werror=implicit-fallthrough=3',
+    '-Werror=maybe-uninitialized',
+#    '-Werror=missing-field-initializers', // fix eek-unicode-keysym-entries first
+  ],
+  language: 'c'
+)
+
 i18n = import('i18n')
 
 conf_data = configuration_data()
diff --git a/tests/eek-simple-test.c b/tests/eek-simple-test.c
index 2a7753e4..8750026d 100644
--- a/tests/eek-simple-test.c
+++ b/tests/eek-simple-test.c
@@ -19,6 +19,8 @@
  */
 #include "eek/eek.h"
 
+#include <gtk/gtk.h>
+
 static void
 test_create (void)
 {