diff --git a/routers/api/v1/user/watch.go b/routers/api/v1/user/watch.go
index e54709b599f..1fc736deba5 100644
--- a/routers/api/v1/user/watch.go
+++ b/routers/api/v1/user/watch.go
@@ -114,6 +114,8 @@ func IsWatching(ctx *context.APIContext) {
 	// responses:
 	//   "200":
 	//     "$ref": "#/responses/WatchInfo"
+	//   "404":
+	//     description: User is not watching this repo or repo do not exist
 
 	if models.IsWatching(ctx.User.ID, ctx.Repo.Repository.ID) {
 		ctx.JSON(http.StatusOK, api.WatchInfo{
diff --git a/templates/swagger/v1_json.tmpl b/templates/swagger/v1_json.tmpl
index 5de98a72ce8..8cb7dbfcc0e 100644
--- a/templates/swagger/v1_json.tmpl
+++ b/templates/swagger/v1_json.tmpl
@@ -7411,6 +7411,9 @@
         "responses": {
           "200": {
             "$ref": "#/responses/WatchInfo"
+          },
+          "404": {
+            "description": "User is not watching this repo or repo do not exist"
           }
         }
       },