diff --git a/.changeset/brave-experts-cheer.md b/.changeset/brave-experts-cheer.md
new file mode 100644
index 0000000..825d384
--- /dev/null
+++ b/.changeset/brave-experts-cheer.md
@@ -0,0 +1,5 @@
+---
+"@primer/behaviors": patch
+---
+
+Update `anchored-position.ts` to support handling elements outside of `document.body` in `getClippingRect`
diff --git a/src/anchored-position.ts b/src/anchored-position.ts
index fbc67e7..ca7a5a3 100644
--- a/src/anchored-position.ts
+++ b/src/anchored-position.ts
@@ -207,7 +207,7 @@ function isOnTopLayer(element: Element) {
 function getClippingRect(element: Element): BoxPosition {
   let parentNode: typeof element.parentNode = element
   while (parentNode !== null) {
-    if (parentNode === document.body) {
+    if (!(parentNode instanceof Element)) {
       break
     }
     const parentNodeStyle = getComputedStyle(parentNode as Element)