diff --git a/routers/api/v1/repo/issue.go b/routers/api/v1/repo/issue.go
index 937b581a6d..a064482498 100644
--- a/routers/api/v1/repo/issue.go
+++ b/routers/api/v1/repo/issue.go
@@ -198,6 +198,7 @@ func ListIssues(ctx *context.APIContext) {
 	//   in: query
 	//   description: whether issue is open or closed
 	//   type: string
+	//   enum: [closed, open, all]
 	// - name: labels
 	//   in: query
 	//   description: comma separated list of labels. Fetch only issues that have any of this labels. Non existent labels are discarded
@@ -210,6 +211,7 @@ func ListIssues(ctx *context.APIContext) {
 	//   in: query
 	//   description: filter by type (issues / pulls) if set
 	//   type: string
+	//   enum: [issues, pulls]
 	// - name: milestones
 	//   in: query
 	//   description: comma separated list of milestone names or ids. It uses names and fall back to ids. Fetch only issues that have any of this milestones. Non existent milestones are discarded
diff --git a/templates/swagger/v1_json.tmpl b/templates/swagger/v1_json.tmpl
index 1226822cc8..9290bfe079 100644
--- a/templates/swagger/v1_json.tmpl
+++ b/templates/swagger/v1_json.tmpl
@@ -3776,6 +3776,11 @@
             "required": true
           },
           {
+            "enum": [
+              "closed",
+              "open",
+              "all"
+            ],
             "type": "string",
             "description": "whether issue is open or closed",
             "name": "state",
@@ -3794,6 +3799,10 @@
             "in": "query"
           },
           {
+            "enum": [
+              "issues",
+              "pulls"
+            ],
             "type": "string",
             "description": "filter by type (issues / pulls) if set",
             "name": "type",