diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index 68cb1238..8b462fed 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -14,6 +14,12 @@ Change Log
 Unreleased
 ----------
 
+[9.0.1] - 2023-10-31
+--------------------
+Changed
+~~~~~~~
+* Fixed key error in merging event producer configs. Previously, setting only one of `enabled` or `event_key_field` would result in a KeyError being thrown
+
 [9.0.0] - 2023-10-04
 --------------------
 Changed
diff --git a/openedx_events/__init__.py b/openedx_events/__init__.py
index 977cc1ca..c2a68c7f 100644
--- a/openedx_events/__init__.py
+++ b/openedx_events/__init__.py
@@ -5,4 +5,4 @@
 more information about the project.
 """
 
-__version__ = "9.0.0"
+__version__ = "9.0.1"
diff --git a/openedx_events/event_bus/__init__.py b/openedx_events/event_bus/__init__.py
index 6d508146..e0fcc332 100644
--- a/openedx_events/event_bus/__init__.py
+++ b/openedx_events/event_bus/__init__.py
@@ -204,8 +204,12 @@ def merge_producer_configs(producer_config_original, producer_config_overrides):
         event_type_config_combined = combined.get(event_type, {})
         for topic, topic_config_overrides in event_type_config_overrides.items():
             topic_config_combined = event_type_config_combined.get(topic, {})
-            topic_config_combined['enabled'] = topic_config_overrides['enabled']
-            topic_config_combined['event_key_field'] = topic_config_overrides['event_key_field']
+            enabled_override = topic_config_overrides.get('enabled', None)
+            event_key_field_override = topic_config_overrides.get('event_key_field', None)
+            if enabled_override is not None:
+                topic_config_combined['enabled'] = enabled_override
+            if event_key_field_override is not None:
+                topic_config_combined['event_key_field'] = event_key_field_override
             event_type_config_combined[topic] = topic_config_combined
         combined[event_type] = event_type_config_combined
     return combined
diff --git a/openedx_events/event_bus/tests/test_loader.py b/openedx_events/event_bus/tests/test_loader.py
index ad742458..720f3d7c 100644
--- a/openedx_events/event_bus/tests/test_loader.py
+++ b/openedx_events/event_bus/tests/test_loader.py
@@ -130,8 +130,10 @@ def test_default_does_nothing(self):
 
 
 class TestSettings(TestCase):
-    def test_merge_configs(self):
-        dict_a = {
+
+    def setUp(self) -> None:
+        super().setUp()
+        self.base_config = {
             'event_type_0': {
                 'topic_a': {'event_key_field': 'field', 'enabled': True},
                 'topic_b': {'event_key_field': 'field', 'enabled': True}
@@ -140,13 +142,15 @@ def test_merge_configs(self):
                 'topic_c': {'event_key_field': 'field', 'enabled': True},
             }
         }
+
+    def test_merge_configs(self):
         # for ensuring we didn't change the original dict
-        dict_a_copy = copy.deepcopy(dict_a)
-        dict_b = {
+        base_copy = copy.deepcopy(self.base_config)
+        overrides = {
             'event_type_0': {
-                # disable an existing event/topic pairing
-                'topic_a': {'event_key_field': 'field', 'enabled': False},
-                # add a new topic to an existing topic
+                # disable an existing event/topic pairing and change the key field
+                'topic_a': {'event_key_field': 'new_field', 'enabled': False},
+                # add a new topic to an existing event_type
                 'topic_d': {'event_key_field': 'field', 'enabled': True},
             },
             # add a new event_type
@@ -154,11 +158,11 @@ def test_merge_configs(self):
                 'topic_e': {'event_key_field': 'field', 'enabled': True},
             }
         }
-        dict_b_copy = copy.deepcopy(dict_b)
-        result = merge_producer_configs(dict_a, dict_b)
+        overrides_copy = copy.deepcopy(overrides)
+        result = merge_producer_configs(self.base_config, overrides)
         self.assertDictEqual(result, {
             'event_type_0': {
-                'topic_a': {'event_key_field': 'field', 'enabled': False},
+                'topic_a': {'event_key_field': 'new_field', 'enabled': False},
                 'topic_b': {'event_key_field': 'field', 'enabled': True},
                 'topic_d': {'event_key_field': 'field', 'enabled': True},
             },
@@ -169,19 +173,30 @@ def test_merge_configs(self):
                 'topic_e': {'event_key_field': 'field', 'enabled': True},
             }
         })
-        self.assertDictEqual(dict_a, dict_a_copy)
-        self.assertDictEqual(dict_b, dict_b_copy)
+        self.assertDictEqual(self.base_config, base_copy)
+        self.assertDictEqual(overrides, overrides_copy)
 
     def test_merge_configs_with_empty(self):
-        dict_a = {
+        overrides = {}
+        result = merge_producer_configs(self.base_config, overrides)
+        self.assertDictEqual(result, self.base_config)
+
+    def test_merge_configs_with_partial(self):
+        overrides = {
             'event_type_0': {
-                'topic_a': {'event_key_field': 'field', 'enabled': True},
-                'topic_b': {'event_key_field': 'field', 'enabled': True}
+                # no override for 'event_key_field'
+                'topic_a': {'enabled': False},
+                # no override for 'enabled'
+                'topic_b': {'event_key_field': 'new_field'}
+            }
+        }
+        result = merge_producer_configs(self.base_config, overrides)
+        self.assertDictEqual(result, {
+            'event_type_0': {
+                'topic_a': {'event_key_field': 'field', 'enabled': False},
+                'topic_b': {'event_key_field': 'new_field', 'enabled': True}
             },
             'event_type_1': {
                 'topic_c': {'event_key_field': 'field', 'enabled': True},
             }
-        }
-        dict_b = {}
-        result = merge_producer_configs(dict_a, dict_b)
-        self.assertDictEqual(result, dict_a)
+        })