diff --git a/src/testdir/test_gui.vim b/src/testdir/test_gui.vim
index d030a6a..7f94e6a 100644
--- a/src/testdir/test_gui.vim
+++ b/src/testdir/test_gui.vim
@@ -2,7 +2,7 @@
 
 source shared.vim
 if !CanRunGui()
-  throw 'Skipped, cannot run GUI'
+  throw 'Skipped: cannot run GUI'
 endif
 
 source setup_gui.vim