diff --git a/client/dist/styles/bundle.css b/client/dist/styles/bundle.css
index 07a47a675..72771f52c 100644
--- a/client/dist/styles/bundle.css
+++ b/client/dist/styles/bundle.css
@@ -16229,6 +16229,13 @@ input.checkbox,input.radio,input[type=checkbox],input[type=radio]{
             flex:0 0 83.33333%;
   }
 
+  .cms-edit-form:not(.AssetAdmin) .form-group.htmleditor .form__field-holder,.form--inline .form-group.htmleditor .form__field-holder,.ss-insert-link .form__fieldgroup .form-group.htmleditor .form__field-holder{
+    -webkit-box-flex:0;
+        -ms-flex:0 0 100%;
+            flex:0 0 100%;
+    max-width:calc(895px + 16.66667%);
+  }
+
   .cms-edit-form:not(.AssetAdmin) .form__field-extra-label,.form--inline .form__field-extra-label,.ss-insert-link .form__fieldgroup .form__field-extra-label{
     -webkit-box-flex:0;
         -ms-flex:0 0 16.66667%;
diff --git a/client/src/components/Form/Form.scss b/client/src/components/Form/Form.scss
index 598d2716c..33b872de4 100644
--- a/client/src/components/Form/Form.scss
+++ b/client/src/components/Form/Form.scss
@@ -312,6 +312,13 @@ input.radio {
       @include make-col-span(10);
     }
 
+    // HTML editor to expand to maximise to the space
+    // Max-width to visually match other stacked fields + label
+    .form-group.htmleditor .form__field-holder {
+      @include make-col-span(12);
+      max-width: calc(#{$input-max-width} + 16.66667%);
+    }
+
     .form__field-extra-label {
       @include make-col-span(2);
       @include make-col-offset(0);