diff --git a/trac/htdocs/main.css b/trac/htdocs/main.css
index 74489a8..3c4f88f 100644
--- a/trac/htdocs/main.css
+++ b/trac/htdocs/main.css
@@ -82,7 +82,7 @@ legend {
     background: #fff;
     opacity: 0.7;
 }
-thead {
+thead th {
     background: #88AA77;
     color: #fff;
     font-weight: bold;