diff --git a/clutter/meson.build b/clutter/meson.build
index f6ded46f6..bac66c70c 100644
--- a/clutter/meson.build
+++ b/clutter/meson.build
@@ -17,11 +17,6 @@ if buildtype != 'plain'
     clutter_debug_c_args += [
       '-DCLUTTER_ENABLE_DEBUG',
     ]
-  else
-    clutter_debug_c_args += [
-      '-DG_DISABLE_ASSERT',
-      '-DG_DISABLE_CAST_CHECKS',
-    ]
   endif
 endif
 clutter_debug_c_args = cc.get_supported_arguments(clutter_debug_c_args)
diff --git a/cogl/meson.build b/cogl/meson.build
index 868645c2f..c126558b4 100644
--- a/cogl/meson.build
+++ b/cogl/meson.build
@@ -86,10 +86,6 @@ if buildtype != 'plain'
     cogl_debug_c_args += [
       '-DCOGL_ENABLE_DEBUG',
     ]
-  else
-    cogl_debug_c_args += [
-      '-DG_DISABLE_CAST_CHECKS',
-    ]
   endif
 endif
 cogl_debug_c_args = cc.get_supported_arguments(cogl_debug_c_args)
diff --git a/meson.build b/meson.build
index 9436811d6..a4142c21a 100644
--- a/meson.build
+++ b/meson.build
@@ -519,6 +519,11 @@ if buildtype != 'plain'
     mutter_c_args += [
       '-DG_ENABLE_DEBUG',
     ]
+  else
+    mutter_c_args += [
+      '-DG_DISABLE_ASSERT',
+      '-DG_DISABLE_CAST_CHECKS',
+    ]
   endif
 
   supported_mutter_c_args = cc.get_supported_arguments(mutter_c_args)
diff --git a/mtk/meson.build b/mtk/meson.build
index 71301ad9c..4b2700952 100644
--- a/mtk/meson.build
+++ b/mtk/meson.build
@@ -13,18 +13,6 @@ mtk_c_args = [
   '-DG_LOG_DOMAIN="Mtk"',
 ]
 
-mtk_debug_c_args = []
-if buildtype != 'plain'
-  if not get_option('debug')
-    mtk_debug_c_args += [
-      '-DG_DISABLE_ASSERT',
-      '-DG_DISABLE_CAST_CHECKS',
-    ]
-  endif
-endif
-mtk_debug_c_args = cc.get_supported_arguments(mtk_debug_c_args)
-mtk_c_args += mtk_debug_c_args
-
 mtk_pkg_deps = [
   glib_dep,
   gobject_dep,