diff --git a/git-gui/git-gui.sh b/git-gui/git-gui.sh
index 5bc21b878d413e..3ce2e04bc58ee2 100755
--- a/git-gui/git-gui.sh
+++ b/git-gui/git-gui.sh
@@ -2505,6 +2505,10 @@ proc toggle_or_diff {mode w args} {
 		if {$last_clicked ne {}} {
 			set lno [lindex $last_clicked 1]
 		} else {
+			if {[llength $file_lists($w)] == 0} {
+				set last_clicked {}
+				return
+			}
 			set lno [expr {int([lindex [$w tag ranges in_diff] 0])}]
 		}
 		if {$mode eq "toggle"} {