diff --git a/src/matrix-api-types.c b/src/matrix-api-types.c
index 520ab7f..68093ff 100644
--- a/src/matrix-api-types.c
+++ b/src/matrix-api-types.c
@@ -117,6 +117,7 @@ G_DEFINE_QUARK(matrix-api-error-quark, matrix_api_error);
 
 /**
  * MatrixAPIResizeMethod:
+ * @MATRIX_API_RESIZE_METHOD_DEFAULT: use the server default value
  * @MATRIX_API_RESIZE_METHOD_CROP: crop thumbnail to the requested
  *                                 size
  * @MATRIX_API_RESIZE_METHOD_SCALE: scale thumbnail to the requested
diff --git a/src/matrix-api-types.h b/src/matrix-api-types.h
index 84d114d..5eb30ca 100644
--- a/src/matrix-api-types.h
+++ b/src/matrix-api-types.h
@@ -57,6 +57,7 @@ typedef enum {
 } MatrixAPIEventFormat;
 
 typedef enum {
+    MATRIX_API_RESIZE_METHOD_DEFAULT,
     MATRIX_API_RESIZE_METHOD_CROP,
     MATRIX_API_RESIZE_METHOD_SCALE
 } MatrixAPIResizeMethod;