diff --git a/go.mod b/go.mod
index b395021..72f007c 100644
--- a/go.mod
+++ b/go.mod
@@ -13,7 +13,7 @@ require (
 require (
 	github.com/google/uuid v1.2.0 // indirect
 	golang.org/x/net v0.20.0 // indirect
-	golang.org/x/sync v0.1.0 // indirect
+	golang.org/x/sync v0.1.0
 	golang.zx2c4.com/wireguard/windows v0.5.3
 )
 
diff --git a/handle.go b/handle.go
index 1355914..855b893 100644
--- a/handle.go
+++ b/handle.go
@@ -57,14 +57,6 @@ func (d *Handle) Recv(ip []byte, addr *Address) (int, error) {
 // notice: recvLen not work, use windows.GetOverlappedResult
 // todo: support batch recv
 func (d *Handle) RecvEx(ip []byte, addr *Address, recvLen *uint32, ol *windows.Overlapped) error {
-	err := d.recvEx(ip, addr, recvLen, ol)
-	if err != nil {
-		return handleError(err)
-	}
-	return nil
-}
-
-func (d *Handle) recvEx(ip []byte, addr *Address, recvLen *uint32, ol *windows.Overlapped) error {
 	var ipPtr uintptr
 	if len(ip) > 0 {
 		ipPtr = uintptr(unsafe.Pointer(unsafe.SliceData(ip)))
@@ -82,7 +74,7 @@ func (d *Handle) recvEx(ip []byte, addr *Address, recvLen *uint32, ol *windows.O
 		uintptr(unsafe.Pointer(ol)),      // lpOverlapped
 	)
 	if r1 == 0 {
-		return e
+		return handleError(e)
 	}
 	return nil
 }
diff --git a/handle_test.go b/handle_test.go
index 9b2669b..593800b 100644
--- a/handle_test.go
+++ b/handle_test.go
@@ -134,7 +134,7 @@ func Test_Recv_Error(t *testing.T) {
 		defer d.Close()
 
 		_, err = d.Recv(make([]byte, 1536), nil)
-		require.True(t, errors.Is(err, ErrClosed{}))
+		require.True(t, errors.Is(err, ErrClosed{}), err)
 	})
 
 	t.Run("recv/close", func(t *testing.T) {
@@ -148,7 +148,7 @@ func Test_Recv_Error(t *testing.T) {
 				require.NoError(t, d.Close())
 			}()
 			_, err = d.Recv(make([]byte, 1536), nil)
-			require.True(t, errors.Is(err, ErrClosed{}))
+			require.True(t, errors.Is(err, ErrClosed{}), err)
 		}
 	})
 
@@ -163,9 +163,9 @@ func Test_Recv_Error(t *testing.T) {
 				require.NoError(t, d.Close())
 			}()
 			_, err = d.Recv(make([]byte, 1536), nil)
-			require.True(t, errors.Is(err, ErrClosed{}))
+			require.True(t, errors.Is(err, ErrClosed{}), err)
 
-			require.True(t, errors.Is(d.Close(), ErrClosed{}))
+			require.True(t, errors.Is(d.Close(), ErrClosed{}), err)
 		}
 	})
 
@@ -181,14 +181,14 @@ func Test_Recv_Error(t *testing.T) {
 			}()
 			{
 				_, err = d.Recv(make([]byte, 1536), nil)
-				require.True(t, errors.Is(err, ErrClosed{}))
+				require.True(t, errors.Is(err, ErrClosed{}), err)
 			}
 			{
-				require.True(t, errors.Is(d.Close(), ErrClosed{}))
+				require.True(t, errors.Is(d.Close(), ErrClosed{}), err)
 			}
 			{
 				_, err = d.Recv(make([]byte, 1536), nil)
-				require.True(t, errors.Is(err, ErrClosed{}))
+				require.True(t, errors.Is(err, ErrClosed{}), err)
 			}
 		}
 	})
@@ -200,7 +200,7 @@ func Test_Recv_Error(t *testing.T) {
 		defer d.Close()
 
 		n, err := d.Recv(make([]byte, 1536), nil)
-		require.True(t, errors.Is(err, ErrShutdown{}))
+		require.True(t, errors.Is(err, ErrShutdown{}), err)
 		require.Zero(t, n)
 	})
 
@@ -215,7 +215,7 @@ func Test_Recv_Error(t *testing.T) {
 		}()
 
 		n, err := d.Recv(make([]byte, 1536), nil)
-		require.True(t, errors.Is(err, ErrShutdown{}))
+		require.True(t, errors.Is(err, ErrShutdown{}), err)
 		require.Zero(t, n)
 	})
 
@@ -230,7 +230,7 @@ func Test_Recv_Error(t *testing.T) {
 		}()
 
 		n, err := d.Recv(make([]byte, 1536), nil)
-		require.True(t, errors.Is(err, ErrShutdown{}))
+		require.True(t, errors.Is(err, ErrShutdown{}), err)
 		require.Zero(t, n)
 
 		require.NoError(t, d.Shutdown(Both))
@@ -248,7 +248,7 @@ func Test_Recv_Error(t *testing.T) {
 
 		{
 			n, err := d.Recv(make([]byte, 1536), nil)
-			require.True(t, errors.Is(err, ErrShutdown{}))
+			require.True(t, errors.Is(err, ErrShutdown{}), err)
 			require.Zero(t, n)
 		}
 		{
@@ -256,7 +256,7 @@ func Test_Recv_Error(t *testing.T) {
 		}
 		{
 			n, err := d.Recv(make([]byte, 1536), nil)
-			require.True(t, errors.Is(err, ErrShutdown{}))
+			require.True(t, errors.Is(err, ErrShutdown{}), err)
 			require.Zero(t, n)
 		}
 	})
@@ -270,7 +270,7 @@ func Test_Recv_Error(t *testing.T) {
 		require.NoError(t, err)
 
 		n, err := d.Recv(make([]byte, 1536), nil)
-		require.True(t, errors.Is(err, ErrClosed{}))
+		require.True(t, errors.Is(err, ErrClosed{}), err)
 		require.Zero(t, n)
 	})
 }