diff --git a/packages/overlay/src/overlay-stack.ts b/packages/overlay/src/overlay-stack.ts
index 3b30d6c3a6..8556fdb225 100644
--- a/packages/overlay/src/overlay-stack.ts
+++ b/packages/overlay/src/overlay-stack.ts
@@ -56,6 +56,7 @@ export class OverlayStack {
             <style>
             #actual {
                 position: relative;
+                height: 100%;
                 z-index: 0;
             }
             #holder {