diff --git a/include/aws/mqtt/mqtt.h b/include/aws/mqtt/mqtt.h
index 9fc8001c..974c4576 100644
--- a/include/aws/mqtt/mqtt.h
+++ b/include/aws/mqtt/mqtt.h
@@ -80,6 +80,7 @@ enum aws_mqtt_error {
     AWS_ERROR_MQTT5_INVALID_UTF8_STRING,
     AWS_ERROR_MQTT_CONNECTION_RESET_FOR_ADAPTER_CONNECT,
     AWS_ERROR_MQTT_CONNECTION_RESUBSCRIBE_NO_TOPICS,
+    AWS_ERROR_MQTT_CONNECTION_SUBSCRIBE_FAILURE,
 
     AWS_ERROR_END_MQTT_RANGE = AWS_ERROR_ENUM_END_RANGE(AWS_C_MQTT_PACKAGE_ID),
 };
diff --git a/source/mqtt.c b/source/mqtt.c
index ac8c4529..c87ec0cc 100644
--- a/source/mqtt.c
+++ b/source/mqtt.c
@@ -230,6 +230,9 @@ bool aws_mqtt_is_valid_topic_filter(const struct aws_byte_cursor *topic_filter)
             AWS_DEFINE_ERROR_INFO_MQTT(
                 AWS_ERROR_MQTT_CONNECTION_RESUBSCRIBE_NO_TOPICS,
                 "Resubscribe was called when there were no subscriptions"),
+            AWS_DEFINE_ERROR_INFO_MQTT(
+                AWS_ERROR_MQTT_CONNECTION_SUBSCRIBE_FAILURE,
+                "MQTT subscribe operation failed"),
         };
 /* clang-format on */
 #undef AWS_DEFINE_ERROR_INFO_MQTT