diff --git a/src/matrix-api-types.c b/src/matrix-api-types.c
index 68093ff..193e319 100644
--- a/src/matrix-api-types.c
+++ b/src/matrix-api-types.c
@@ -36,6 +36,7 @@
  *                                        (e.g. connection error)
  * @MATRIX_API_ERROR_INCOMPLETE: the passed/generated data is
  *                               incomplete
+ * @MATRIX_API_ERROR_BAD_REQUEST: the request is invalid
  * @MATRIX_API_ERROR_BAD_RESPONSE: malformed response, or the response
  *                                 is not a JSON object
  * @MATRIX_API_ERROR_INVALID_ROOM_ID: the provided string doesn’t
diff --git a/src/matrix-api-types.h b/src/matrix-api-types.h
index 5eb30ca..3d3ef30 100644
--- a/src/matrix-api-types.h
+++ b/src/matrix-api-types.h
@@ -28,6 +28,7 @@ typedef enum {
     MATRIX_API_ERROR_NONE,
     MATRIX_API_ERROR_COMMUNICATION_ERROR,
     MATRIX_API_ERROR_INCOMPLETE,
+    MATRIX_API_ERROR_BAD_REQUEST,
     MATRIX_API_ERROR_BAD_RESPONSE,
     MATRIX_API_ERROR_INVALID_ROOM_ID,