diff --git a/changelog.d/11700.removal b/changelog.d/11700.removal
new file mode 100644
index 000000000..d3d3c48f0
--- /dev/null
+++ b/changelog.d/11700.removal
@@ -0,0 +1 @@
+Remove workaround introduced in Synapse 1.50.0 for Mjolnir compatibility. Breaks compatibility with Mjolnir 1.3.1 and earlier.
diff --git a/docs/upgrade.md b/docs/upgrade.md
index 0d0bb066e..95005962d 100644
--- a/docs/upgrade.md
+++ b/docs/upgrade.md
@@ -106,6 +106,14 @@ You will need to ensure `synctl` is on your `PATH`.
     automatically, though you might need to activate a virtual environment
     depending on how you installed Synapse.
 
+
+## Compatibility dropped for Mjolnir 1.3.1 and earlier
+
+Synapse v1.55.0 drops support for Mjolnir 1.3.1 and earlier.
+If you use the Mjolnir module to moderate your homeserver,
+please upgrade Mjolnir to version 1.3.2 or later before upgrading Synapse.
+
+
 # Upgrading to v1.54.0
 
 ## Legacy structured logging configuration removal
diff --git a/synapse/util/__init__.py b/synapse/util/__init__.py
index 58b4220ff..d8046b755 100644
--- a/synapse/util/__init__.py
+++ b/synapse/util/__init__.py
@@ -31,13 +31,6 @@ 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__)