diff --git a/src/st/st-theme-node-drawing.c b/src/st/st-theme-node-drawing.c
index 9f7e6b6ca..a7fb24ab8 100644
--- a/src/st/st-theme-node-drawing.c
+++ b/src/st/st-theme-node-drawing.c
@@ -229,9 +229,9 @@ unpremultiply (ClutterColor *color)
 {
   if (color->alpha != 0)
     {
-      color->red = (color->red * 255 + 127) / color->alpha;
-      color->green = (color->green * 255 + 127) / color->alpha;
-      color->blue = (color->blue * 255 + 127) / color->alpha;
+      color->red = MIN((color->red * 255 + 127) / color->alpha, 255);
+      color->green = MIN((color->green * 255 + 127) / color->alpha, 255);
+      color->blue = MIN((color->blue * 255 + 127) / color->alpha, 255);
     }
 }