diff --git a/changelog.d/11696.misc b/changelog.d/11696.misc
new file mode 100644
index 0000000000000000000000000000000000000000..e8f39dde18f8670d98495b3da79d6b5acf29d756
--- /dev/null
+++ b/changelog.d/11696.misc
@@ -0,0 +1 @@
+Work around Mjolnir compatibility issue by adding an import for `glob_to_regex` in `synapse.util`, where it moved from.
\ No newline at end of file
diff --git a/synapse/util/__init__.py b/synapse/util/__init__.py
index f157132210dd9bb3e64dd10017f7605595c8ee01..511f52534b3cb10e2faf3ff408d85be577e55e5e 100644
--- a/synapse/util/__init__.py
+++ b/synapse/util/__init__.py
@@ -31,6 +31,13 @@ from synapse.logging import context
 if typing.TYPE_CHECKING:
     pass
 
+# FIXME Mjolnir imports glob_to_regex from this file, but it was moved to
+#       matrix_common.
+#       As a temporary workaround, we import glob_to_regex here for
+#       compatibility with current versions of Mjolnir.
+# See https://github.com/matrix-org/mjolnir/pull/174
+from matrix_common.regex import glob_to_regex  # noqa
+
 logger = logging.getLogger(__name__)