diff --git a/proxy/proxy.go b/proxy/proxy.go
index 213e5ce..c0f6592 100644
--- a/proxy/proxy.go
+++ b/proxy/proxy.go
@@ -111,7 +111,11 @@ func (s *ProxyServer) checkUpstreams() {
 	backup := false
 
 	for i, v := range s.upstreams {
-		if v.Check() && !backup {
+		ok, err := v.Check()
+		if err != nil {
+			log.Printf("Upstream %v didn't pass check: %v", v.Name, err)
+		}
+		if ok && !backup {
 			candidate = int32(i)
 			backup = true
 		}
diff --git a/rpc/rpc.go b/rpc/rpc.go
index 81003fc..cfce3ce 100644
--- a/rpc/rpc.go
+++ b/rpc/rpc.go
@@ -143,13 +143,13 @@ func (r *RPCClient) doPost(url, method string, params interface{}) (JSONRpcResp,
 	return rpcResp, err
 }
 
-func (r *RPCClient) Check() bool {
+func (r *RPCClient) Check() (bool, error) {
 	_, err := r.GetWork()
 	if err != nil {
-		return false
+		return false, err
 	}
 	r.markAlive()
-	return !r.Sick()
+	return !r.Sick(), nil
 }
 
 func (r *RPCClient) Sick() bool {