diff --git a/clutter/cogl/common/cogl-bitmap-fallback.c b/clutter/cogl/common/cogl-bitmap-fallback.c
index a7e9704d9..e750a7ccf 100644
--- a/clutter/cogl/common/cogl-bitmap-fallback.c
+++ b/clutter/cogl/common/cogl-bitmap-fallback.c
@@ -416,7 +416,7 @@ _cogl_bitmap_fallback_premult (const CoglBitmap *bmp,
 
   /* Initialize destination bitmap */
   *dst_bmp = *bmp;
-  dst_bmp->format = (bmp->format & COGL_UNPREMULT_MASK);
+  dst_bmp->format |= COGL_PREMULT_BIT;
 
   /* Allocate a new buffer to hold converted data */
   dst_bmp->data = g_malloc (sizeof(guchar)