diff --git a/mozilla/layout/html/document/src/ua.css b/mozilla/layout/html/document/src/ua.css
index 37bfb8e0f5a..6eda38f8f8f 100644
--- a/mozilla/layout/html/document/src/ua.css
+++ b/mozilla/layout/html/document/src/ua.css
@@ -989,6 +989,8 @@ option {
   display:block;
   padding-left:3px;
   padding-right:3px;
+  font-family: sans-serif;
+  font-size: small;
 }
 
 select[disabled] option {
diff --git a/mozilla/layout/style/ua.css b/mozilla/layout/style/ua.css
index 37bfb8e0f5a..6eda38f8f8f 100644
--- a/mozilla/layout/style/ua.css
+++ b/mozilla/layout/style/ua.css
@@ -989,6 +989,8 @@ option {
   display:block;
   padding-left:3px;
   padding-right:3px;
+  font-family: sans-serif;
+  font-size: small;
 }
 
 select[disabled] option {