diff --git a/src/Squidex/app/theme/_bootstrap-vars.scss b/src/Squidex/app/theme/_bootstrap-vars.scss
index 442dc3b5a..5f52efe26 100644
--- a/src/Squidex/app/theme/_bootstrap-vars.scss
+++ b/src/Squidex/app/theme/_bootstrap-vars.scss
@@ -1,12 +1,12 @@
 @import '_mixins.scss';
 @import '_vars.scss';
 
-$font-size-h1:              1.25rem;
-$font-size-h2:              1.2rem;
-$font-size-h3:              1.15rem;
-$font-size-h4:              1.1rem;
-$font-size-h5:              1.05rem;
-$font-size-h6:              1rem;
+$h1-font-size:              1.25rem;
+$h2-font-size:              1.2rem;
+$h3-font-size:              1.15rem;
+$h4-font-size:              1.1rem;
+$h5-font-size:              1.05rem;
+$h6-font-size:              1rem;
 
 $body-bg:                   $color-background;