diff --git a/src/shell-blur-effect.c b/src/shell-blur-effect.c
index e40bb542a..002232746 100644
--- a/src/shell-blur-effect.c
+++ b/src/shell-blur-effect.c
@@ -158,7 +158,7 @@ struct _ShellBlurEffect
   ClutterEffect parent_instance;
 
   ClutterActor *actor;
-  uint8_t old_opacity_override;
+  int old_opacity_override;
 
   BlurData blur[2];