diff --git a/rpcx/internal/codes/accept_test.go b/rpcx/internal/codes/accept_test.go
new file mode 100644
index 00000000..ddca4a08
--- /dev/null
+++ b/rpcx/internal/codes/accept_test.go
@@ -0,0 +1,34 @@
+package codes
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
+)
+
+func TestAccept(t *testing.T) {
+	tests := []struct {
+		name   string
+		err    error
+		accept bool
+	}{
+		{
+			name:   "nil error",
+			err:    nil,
+			accept: true,
+		},
+		{
+			name:   "deadline error",
+			err:    status.Error(codes.DeadlineExceeded, "deadline"),
+			accept: false,
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			assert.Equal(t, test.accept, Acceptable(test.err))
+		})
+	}
+}