diff --git a/wagtail/wagtailadmin/static/wagtailadmin/css/components/forms.less b/wagtail/wagtailadmin/static/wagtailadmin/css/components/forms.less
index 6e6647f3b..5b50b2621 100644
--- a/wagtail/wagtailadmin/static/wagtailadmin/css/components/forms.less
+++ b/wagtail/wagtailadmin/static/wagtailadmin/css/components/forms.less
@@ -158,6 +158,7 @@ input[type=submit], input[type=reset], input[type=button], .button, button{
     display:inline-block;
     overflow:hidden;
     position:relative;
+    font-weight:normal;
 
     &.button-small{
         font-size:0.95em;