diff --git a/src/MacVim/MMVimView.m b/src/MacVim/MMVimView.m
index f5e8f68ba8..a175f897a7 100644
--- a/src/MacVim/MMVimView.m
+++ b/src/MacVim/MMVimView.m
@@ -393,6 +393,7 @@ enum {
     //NSLog(@"Set thumb value %.2f proportion %.2f for scroller %d",
     //        val, prop, ident);
     [scroller setFloatValue:val knobProportion:prop];
+    [scroller setEnabled:prop != 1.f];
 }