diff --git a/src/pyj/read_book/anchor_visibility.pyj b/src/pyj/read_book/anchor_visibility.pyj
index 5c30ec1003..f97cf501ea 100644
--- a/src/pyj/read_book/anchor_visibility.pyj
+++ b/src/pyj/read_book/anchor_visibility.pyj
@@ -24,7 +24,7 @@ def ensure_anchor_cache_valid():
 def ensure_page_list_target_is_displayed(elem):
     # The stupid EPUB 3 examples have page list links pointing to
     # display:none divs. Sigh.
-    if window.getComputedStyle(elem).display is 'none':
+    if elem and window.getComputedStyle(elem).display is 'none':
         elem.textContent = ''
         elem.setAttribute('style', 'all: revert')