diff --git a/synapse/push/bulk_push_rule_evaluator.py b/synapse/push/bulk_push_rule_evaluator.py
index 36f5ccf5f64f..264dd7f17949 100644
--- a/synapse/push/bulk_push_rule_evaluator.py
+++ b/synapse/push/bulk_push_rule_evaluator.py
@@ -540,9 +540,7 @@ def _flatten_dict(
             # nested fields.
             key = key.replace("\\", "\\\\").replace(".", "\\.")
 
-        if isinstance(value, str):
-            result[".".join(prefix + [key])] = value.lower()
-        elif isinstance(value, bool) or type(value) is int or value is None:
+        if isinstance(value, (bool, str)) or type(value) is int or value is None:
             result[".".join(prefix + [key])] = value
         elif isinstance(value, Mapping):
             # do not set `room_version` due to recursion considerations below
diff --git a/tests/push/test_push_rule_evaluator.py b/tests/push/test_push_rule_evaluator.py
index 4adce2be892c..a24976e997da 100644
--- a/tests/push/test_push_rule_evaluator.py
+++ b/tests/push/test_push_rule_evaluator.py
@@ -427,12 +427,11 @@ def test_exact_event_match_string(self) -> None:
             {"value": "foobaz"},
             "exact value should match",
         )
-        # TODO?
-        # self._assert_not_matches(
-        #     condition,
-        #     {"value": "FoobaZ"},
-        #     "values should match and be case-sensitive",
-        # )
+        self._assert_not_matches(
+            condition,
+            {"value": "FoobaZ"},
+            "values should match and be case-sensitive",
+        )
         self._assert_not_matches(
             condition,
             {"value": "test foobaz test"},