diff --git a/packages/block-editor/src/components/block-tools/style.scss b/packages/block-editor/src/components/block-tools/style.scss
index ca618dcdee6aef..8647b417d720d5 100644
--- a/packages/block-editor/src/components/block-tools/style.scss
+++ b/packages/block-editor/src/components/block-tools/style.scss
@@ -325,7 +325,16 @@
 			width: auto;
 		}
 	}
+}
 
+body.site-editor-php {
+	.block-editor-block-contextual-toolbar {
+		@include break-large() {
+			&.is-fixed {
+				width: calc(100% - 240px - #{4 * $grid-unit-80});
+			}
+		}
+	}
 }
 
 /**