diff --git a/git-gui b/git-gui
index 3e53fbd623..afd9ac026e 100755
--- a/git-gui
+++ b/git-gui
@@ -1716,9 +1716,7 @@ unset filemask i
 
 proc is_MacOSX {} {
 	global tcl_platform tk_library
-	if {$tcl_platform(platform) eq {unix}
-		&& $tcl_platform(os) eq {Darwin}
-		&& [string match /Library/Frameworks/* $tk_library]} {
+	if {[tk windowingsystem] eq {aqua}} {
 		return 1
 	}
 	return 0