diff --git a/datasette/static/app.css b/datasette/static/app.css
index c89f412b..7988252e 100644
--- a/datasette/static/app.css
+++ b/datasette/static/app.css
@@ -119,7 +119,8 @@ h6,
   font-weight: 700;
   font-size: 1rem;
   margin: 0;
-  padding: 0
+  padding: 0;
+  word-break: break-word;
 }
 h1,
 .header1 {