diff --git a/fb/fbpict.c b/fb/fbpict.c
index 3ff609f77..cd6cac277 100644
--- a/fb/fbpict.c
+++ b/fb/fbpict.c
@@ -1175,7 +1175,12 @@ fbComposite (CARD8      op,
 			func = fbCompositeSrc_8888x0888;
 			break;
 		    case PICT_r5g6b5:
-			func = fbCompositeSrc_8888x0565;
+#ifdef USE_MMX
+			if (fbHaveMMX())
+			    func = fbCompositeSrc_8888x0565mmx;
+			else
+#endif
+			    func = fbCompositeSrc_8888x0565;
 			break;
 		    default:
 			break;
@@ -1221,7 +1226,12 @@ fbComposite (CARD8      op,
 			func = fbCompositeSrc_8888x0888;
 			break;
 		    case PICT_b5g6r5:
-			func = fbCompositeSrc_8888x0565;
+#ifdef USE_MMX
+			if (fbHaveMMX())
+			    func = fbCompositeSrc_8888x0565mmx;
+			else
+#endif
+			    func = fbCompositeSrc_8888x0565;
 			break;
 		    default:
 			break;