diff --git a/README.rst b/README.rst
index 47bb4dd..6900bfc 100644
--- a/README.rst
+++ b/README.rst
@@ -79,6 +79,10 @@ Caveats
 
       See also `issue #1`_.
 
+    * A regression in Sphinx version 7.2 prevents the extension from working
+      properly when using the `.. include` directive. See `Sphinx issue
+      #11643`_.
+
     * In Sphinx versions 5.0 and 5.1, there has been
       a regression in how dependencies are determined.
       This could lead to spurious dependencies
@@ -117,3 +121,4 @@ Similar stuff
     guides/feature-flags.html
 .. _issue #1: https://github.com/mgeier/sphinx-last-updated-by-git/issues/1
 .. _issue #40: https://github.com/mgeier/sphinx-last-updated-by-git/issues/40
+.. _Sphinx issue #11643: https://github.com/sphinx-doc/sphinx/issues/11643
diff --git a/src/sphinx_last_updated_by_git.py b/src/sphinx_last_updated_by_git.py
index d4b14d7..0bf1b34 100644
--- a/src/sphinx_last_updated_by_git.py
+++ b/src/sphinx_last_updated_by_git.py
@@ -276,8 +276,10 @@ def _builder_inited(app):
 
 def _source_read(app, docname, source):
     env = app.env
-    assert docname not in env.git_last_updated
-    env.git_last_updated[docname] = None
+    # Since Sphinx 7.2, the source-read hook can be called multiple times
+    # when using .. include
+    if docname not in env.git_last_updated:
+        env.git_last_updated[docname] = None
 
 
 def _env_merge_info(app, env, docnames, other):