diff --git a/changelog.d/14356.bugfix b/changelog.d/14356.bugfix
new file mode 100644
index 0000000000..288d58a540
--- /dev/null
+++ b/changelog.d/14356.bugfix
@@ -0,0 +1 @@
+Fix a bug introduced in 1.66 which would not send certain pushrules to clients. Contributed by Nico.
diff --git a/synapse/push/clientformat.py b/synapse/push/clientformat.py
index 7095ae83f9..622a1e35c5 100644
--- a/synapse/push/clientformat.py
+++ b/synapse/push/clientformat.py
@@ -44,6 +44,12 @@ def format_push_rules_for_user(
 
         rulearray.append(template_rule)
 
+        pattern_type = template_rule.pop("pattern_type", None)
+        if pattern_type == "user_id":
+            template_rule["pattern"] = user.to_string()
+        elif pattern_type == "user_localpart":
+            template_rule["pattern"] = user.localpart
+
         template_rule["enabled"] = enabled
 
         if "conditions" not in template_rule:
@@ -93,10 +99,14 @@ def _rule_to_template(rule: PushRule) -> Optional[Dict[str, Any]]:
         if len(rule.conditions) != 1:
             return None
         thecond = rule.conditions[0]
-        if "pattern" not in thecond:
-            return None
+
         templaterule = {"actions": rule.actions}
-        templaterule["pattern"] = thecond["pattern"]
+        if "pattern" in thecond:
+            templaterule["pattern"] = thecond["pattern"]
+        elif "pattern_type" in thecond:
+            templaterule["pattern_type"] = thecond["pattern_type"]
+        else:
+            return None
     else:
         # This should not be reached unless this function is not kept in sync
         # with PRIORITY_CLASS_INVERSE_MAP.