diff --git a/src/shell-blur-effect.c b/src/shell-blur-effect.c
index 13842082c..d362b0a20 100644
--- a/src/shell-blur-effect.c
+++ b/src/shell-blur-effect.c
@@ -854,7 +854,7 @@ shell_blur_effect_set_radius (ShellBlurEffect *self,
 float
 shell_blur_effect_get_brightness (ShellBlurEffect *self)
 {
-  g_return_val_if_fail (SHELL_IS_BLUR_EFFECT (self), FALSE);
+  g_return_val_if_fail (SHELL_IS_BLUR_EFFECT (self), -1);
 
   return self->brightness;
 }
@@ -880,7 +880,7 @@ shell_blur_effect_set_brightness (ShellBlurEffect *self,
 ShellBlurMode
 shell_blur_effect_get_mode (ShellBlurEffect *self)
 {
-  g_return_val_if_fail (SHELL_IS_BLUR_EFFECT (self), -1);
+  g_return_val_if_fail (SHELL_IS_BLUR_EFFECT (self), SHELL_BLUR_MODE_ACTOR);
 
   return self->mode;
 }
diff --git a/src/shell-screenshot.c b/src/shell-screenshot.c
index c592a4d7c..fc1b2375b 100644
--- a/src/shell-screenshot.c
+++ b/src/shell-screenshot.c
@@ -868,11 +868,11 @@ shell_screenshot_screenshot_stage_to_content_finish (ShellScreenshot   *screensh
 {
   ClutterContent *content;
 
-  g_return_val_if_fail (SHELL_IS_SCREENSHOT (screenshot), FALSE);
-  g_return_val_if_fail (G_IS_TASK (result), FALSE);
+  g_return_val_if_fail (SHELL_IS_SCREENSHOT (screenshot), NULL);
+  g_return_val_if_fail (G_IS_TASK (result), NULL);
   g_return_val_if_fail (g_async_result_is_tagged (result,
                                                   shell_screenshot_screenshot_stage_to_content),
-                        FALSE);
+                        NULL);
 
   content = g_task_propagate_pointer (G_TASK (result), error);
   if (!content)
@@ -1344,10 +1344,10 @@ GdkPixbuf *
 shell_screenshot_composite_to_stream_finish (GAsyncResult  *result,
                                              GError       **error)
 {
-  g_return_val_if_fail (G_IS_TASK (result), FALSE);
+  g_return_val_if_fail (G_IS_TASK (result), NULL);
   g_return_val_if_fail (g_async_result_is_tagged (result,
                                                   shell_screenshot_composite_to_stream),
-                        FALSE);
+                        NULL);
 
   return g_task_propagate_pointer (G_TASK (result), error);
 }