diff --git a/clutter/meson.build b/clutter/meson.build
index 9c365b49e..2529a61d4 100644
--- a/clutter/meson.build
+++ b/clutter/meson.build
@@ -12,18 +12,20 @@ clutter_c_args = [
 ]
 
 clutter_debug_c_args = []
-if get_option('debug')
-  clutter_debug_c_args += [
-    '-DCLUTTER_ENABLE_DEBUG',
-    '-fno-omit-frame-pointer'
-  ]
-elif buildtype != 'plain'
-  clutter_debug_c_args += [
-    '-DG_DISABLE_ASSERT',
-    '-DG_DISABLE_CAST_CHECKS',
-  ]
+if buildtype != 'plain'
+  if get_option('debug')
+    clutter_debug_c_args += [
+      '-DCLUTTER_ENABLE_DEBUG',
+      '-fno-omit-frame-pointer',
+    ]
+  else
+    clutter_debug_c_args += [
+      '-DG_DISABLE_ASSERT',
+      '-DG_DISABLE_CAST_CHECKS',
+    ]
+  endif
 endif
-supported_clutter_debug_c_args = cc.get_supported_arguments(clutter_debug_c_args)
+clutter_debug_c_args = cc.get_supported_arguments(clutter_debug_c_args)
 clutter_c_args += clutter_debug_c_args
 
 clutter_pkg_deps = [
diff --git a/cogl/meson.build b/cogl/meson.build
index 3904e8eba..51f4b1550 100644
--- a/cogl/meson.build
+++ b/cogl/meson.build
@@ -84,20 +84,21 @@ if have_gles2
 endif
 
 cogl_debug_c_args = []
-buildtype = get_option('buildtype')
-if get_option('debug')
-  cogl_debug_c_args += [
-    '-DCOGL_GL_DEBUG',
-    '-DCOGL_OBJECT_DEBUG',
-    '-DCOGL_ENABLE_DEBUG',
-    '-fno-omit-frame-pointer'
-  ]
-elif buildtype != 'plain'
-  cogl_debug_c_args += [
-    '-DG_DISABLE_CAST_CHECKS'
-  ]
+if buildtype != 'plain'
+  if get_option('debug')
+    cogl_debug_c_args += [
+      '-DCOGL_GL_DEBUG',
+      '-DCOGL_OBJECT_DEBUG',
+      '-DCOGL_ENABLE_DEBUG',
+      '-fno-omit-frame-pointer',
+    ]
+  else
+    cogl_debug_c_args += [
+      '-DG_DISABLE_CAST_CHECKS',
+    ]
+  endif
 endif
-supported_cogl_debug_c_args = cc.get_supported_arguments(cogl_debug_c_args)
+cogl_debug_c_args = cc.get_supported_arguments(cogl_debug_c_args)
 cogl_c_args += cogl_debug_c_args
 
 subdir('cogl')
diff --git a/meson.build b/meson.build
index 2471f9b7d..1c4bfe15e 100644
--- a/meson.build
+++ b/meson.build
@@ -466,7 +466,7 @@ add_project_arguments('-D_GNU_SOURCE', language: 'c')
 
 buildtype = get_option('buildtype')
 if buildtype != 'plain'
-  all_warnings = [
+  mutter_c_args = [
     '-fno-strict-aliasing',
     '-Wpointer-arith',
     '-Wmissing-declarations',
@@ -506,17 +506,16 @@ if buildtype != 'plain'
     '-Wno-missing-field-initializers',
     '-Wno-type-limits',
   ]
-  supported_warnings = cc.get_supported_arguments(all_warnings)
-  add_project_arguments(supported_warnings, language: 'c')
-endif
 
-if get_option('debug')
-  debug_c_args = [
-    '-DG_ENABLE_DEBUG',
-    '-fno-omit-frame-pointer'
-  ]
-  supported_debug_c_args = cc.get_supported_arguments(debug_c_args)
-  add_project_arguments(supported_debug_c_args, language: 'c')
+  if get_option('debug')
+    mutter_c_args += [
+      '-DG_ENABLE_DEBUG',
+      '-fno-omit-frame-pointer',
+    ]
+  endif
+
+  supported_mutter_c_args = cc.get_supported_arguments(mutter_c_args)
+  add_project_arguments(supported_mutter_c_args, language: 'c')
 endif
 
 cc.compiles('void main (void) { __builtin_ffsl (0); __builtin_popcountl (0); }')
diff --git a/mtk/meson.build b/mtk/meson.build
index 6e7e347d6..76724fee8 100644
--- a/mtk/meson.build
+++ b/mtk/meson.build
@@ -14,17 +14,19 @@ mtk_c_args = [
 ]
 
 mtk_debug_c_args = []
-if get_option('debug')
-  mtk_debug_c_args += [
-    '-fno-omit-frame-pointer'
-  ]
-elif buildtype != 'plain'
-  mtk_debug_c_args += [
-    '-DG_DISABLE_ASSERT',
-    '-DG_DISABLE_CAST_CHECKS',
-  ]
+if buildtype != 'plain'
+  if get_option('debug')
+    mtk_debug_c_args += [
+      '-fno-omit-frame-pointer'
+    ]
+  else
+    mtk_debug_c_args += [
+      '-DG_DISABLE_ASSERT',
+      '-DG_DISABLE_CAST_CHECKS',
+    ]
+  endif
 endif
-supported_mtk_debug_c_args = cc.get_supported_arguments(mtk_debug_c_args)
+mtk_debug_c_args = cc.get_supported_arguments(mtk_debug_c_args)
 mtk_c_args += mtk_debug_c_args
 
 mtk_pkg_deps = [