diff --git a/routers/api/v1/repo/issue.go b/routers/api/v1/repo/issue.go
index 108504ebb4..c53eb07190 100644
--- a/routers/api/v1/repo/issue.go
+++ b/routers/api/v1/repo/issue.go
@@ -891,13 +891,27 @@ func EditIssue(ctx *context.APIContext) {
 				return
 			}
 		}
-		if err := issue_service.ChangeStatus(ctx, issue, ctx.Doer, "", api.StateClosed == api.StateType(*form.State)); err != nil {
-			if issues_model.IsErrDependenciesLeft(err) {
-				ctx.Error(http.StatusPreconditionFailed, "DependenciesLeft", "cannot close this issue because it still has open dependencies")
+
+		var isClosed bool
+		switch state := api.StateType(*form.State); state {
+		case api.StateOpen:
+			isClosed = false
+		case api.StateClosed:
+			isClosed = true
+		default:
+			ctx.Error(http.StatusPreconditionFailed, "UnknownIssueStateError", fmt.Sprintf("unknown state: %s", state))
+			return
+		}
+
+		if issue.IsClosed != isClosed {
+			if err := issue_service.ChangeStatus(ctx, issue, ctx.Doer, "", isClosed); err != nil {
+				if issues_model.IsErrDependenciesLeft(err) {
+					ctx.Error(http.StatusPreconditionFailed, "DependenciesLeft", "cannot close this issue because it still has open dependencies")
+					return
+				}
+				ctx.Error(http.StatusInternalServerError, "ChangeStatus", err)
 				return
 			}
-			ctx.Error(http.StatusInternalServerError, "ChangeStatus", err)
-			return
 		}
 	}
 
diff --git a/routers/api/v1/repo/pull.go b/routers/api/v1/repo/pull.go
index 148b6ed637..de67057fdd 100644
--- a/routers/api/v1/repo/pull.go
+++ b/routers/api/v1/repo/pull.go
@@ -716,13 +716,27 @@ func EditPullRequest(ctx *context.APIContext) {
 			ctx.Error(http.StatusPreconditionFailed, "MergedPRState", "cannot change state of this pull request, it was already merged")
 			return
 		}
-		if err := issue_service.ChangeStatus(ctx, issue, ctx.Doer, "", api.StateClosed == api.StateType(*form.State)); err != nil {
-			if issues_model.IsErrDependenciesLeft(err) {
-				ctx.Error(http.StatusPreconditionFailed, "DependenciesLeft", "cannot close this pull request because it still has open dependencies")
+
+		var isClosed bool
+		switch state := api.StateType(*form.State); state {
+		case api.StateOpen:
+			isClosed = false
+		case api.StateClosed:
+			isClosed = true
+		default:
+			ctx.Error(http.StatusPreconditionFailed, "UnknownPRStateError", fmt.Sprintf("unknown state: %s", state))
+			return
+		}
+
+		if issue.IsClosed != isClosed {
+			if err := issue_service.ChangeStatus(ctx, issue, ctx.Doer, "", isClosed); err != nil {
+				if issues_model.IsErrDependenciesLeft(err) {
+					ctx.Error(http.StatusPreconditionFailed, "DependenciesLeft", "cannot close this pull request because it still has open dependencies")
+					return
+				}
+				ctx.Error(http.StatusInternalServerError, "ChangeStatus", err)
 				return
 			}
-			ctx.Error(http.StatusInternalServerError, "ChangeStatus", err)
-			return
 		}
 	}
 
diff --git a/services/issue/status.go b/services/issue/status.go
index 9b6c683f4f..967c29bd22 100644
--- a/services/issue/status.go
+++ b/services/issue/status.go
@@ -13,6 +13,9 @@ import (
 )
 
 // ChangeStatus changes issue status to open or closed.
+// closed means the target status
+// Fix me: you should check whether the current issue status is same to the target status before call this function
+// as in function changeIssueStatus we will return WasClosedError, even the issue status and target status are both open
 func ChangeStatus(ctx context.Context, issue *issues_model.Issue, doer *user_model.User, commitID string, closed bool) error {
 	comment, err := issues_model.ChangeIssueStatus(ctx, issue, doer, closed)
 	if err != nil {