diff --git a/app/assets/stylesheets/desktop/compose.scss b/app/assets/stylesheets/desktop/compose.scss
index 55c0d45af..a874ce899 100644
--- a/app/assets/stylesheets/desktop/compose.scss
+++ b/app/assets/stylesheets/desktop/compose.scss
@@ -369,10 +369,11 @@
 
 
     .wmd-input, .wmd-preview-scroller, .wmd-preview {
+      -moz-box-sizing: border-box;
       box-sizing: border-box;
       width: 100%;
       height: 100%;
-      min-height: 100%;
+      min-height: auto;
       padding: 7px;
       margin: 0;
       background-color: $secondary;
@@ -399,6 +400,7 @@
     }
     .textarea-wrapper, .preview-wrapper {
       position: relative;
+      -moz-box-sizing: border-box;
       box-sizing: border-box;
       height: 100%;
       min-height: 100%;