diff --git a/hw/xwin/glx/indirect.c b/hw/xwin/glx/indirect.c
index 38605914a4..59ee17fb10 100644
--- a/hw/xwin/glx/indirect.c
+++ b/hw/xwin/glx/indirect.c
@@ -1597,8 +1597,7 @@ static int
 GetShift(int mask)
 {
     int shift = 0;
-
-    while ((mask &1) == 0) {
+    while (mask > 1) {
         shift++;
         mask >>=1;
     }