diff --git a/gtk-common/common.css b/gtk-common/common.css
index 7cd1d2a..53cf3d4 100644
--- a/gtk-common/common.css
+++ b/gtk-common/common.css
@@ -3020,7 +3020,7 @@ scale highlight, progressbar progress, levelbar block.filled {
 
   scale.horizontal highlight,
   scale.horizontal progressbar progress,
-  progressbar scale.horizontal progress
+  progressbar scale.horizontal progress,
   progressbar.horizontal progress,
   levelbar.horizontal block.filled {
     background-image: