diff --git a/book/external/sphinx-iframes b/book/external/sphinx-iframes
index 5f946a1..7663b1f 160000
--- a/book/external/sphinx-iframes
+++ b/book/external/sphinx-iframes
@@ -1 +1 @@
-Subproject commit 5f946a1db9610aefc54681b1c262680d1575d965
+Subproject commit 7663b1f326e11617a8a35aec7cda0f3d67135551