diff --git a/service/rpc/builder.go b/service/rpc/builder.go
index ab388e8c..b90f60ad 100644
--- a/service/rpc/builder.go
+++ b/service/rpc/builder.go
@@ -107,7 +107,11 @@ func (b *builder) AddDescriptor(descriptors ...interface{}) error {
 			path = "/"
 		}
 		for _, action := range descriptor.Actions {
-			b.bindings[genRPCPath(path, action.Version, action.Name)] = &binding{
+			rpcPath := genRPCPath(path, action.Version, action.Name)
+			if _, ok := b.bindings[rpcPath]; ok {
+				return fmt.Errorf("duplicated rpc path: %s", rpcPath)
+			}
+			b.bindings[rpcPath] = &binding{
 				middlewares: descriptor.Middlewares,
 				definition:  b.genDefinition(action, descriptor.Consumes, descriptor.Produces, descriptor.Tags),
 			}
diff --git a/service/rpc/builder_test.go b/service/rpc/builder_test.go
index fbd90a88..bc3f42cc 100644
--- a/service/rpc/builder_test.go
+++ b/service/rpc/builder_test.go
@@ -303,6 +303,33 @@ func TestDefinitions(t *testing.T) {
 	}
 }
 
+func TestDuplicatedRPCPath(t *testing.T) {
+	const version = "2020-10-10"
+	action := definition.RPCAction{
+		Name:    "GetFoo",
+		Version: version,
+		Function: func() (string, error) {
+			return "", nil
+		},
+		Results: definition.DataErrorResults(""),
+	}
+	desc := definition.RPCDescriptor{
+		Path:        "/",
+		Description: "Test",
+		Consumes:    []string{definition.MIMEAll},
+		Produces:    []string{definition.MIMEAll},
+		Actions:     []definition.RPCAction{action, action},
+	}
+	builder := NewBuilder()
+	err := builder.AddDescriptor(desc)
+	if err == nil {
+		t.Fatal("Unexpected success")
+	}
+	if !strings.Contains(err.Error(), "duplicated rpc path") {
+		t.Fatalf("Unexpected error: %v", err)
+	}
+}
+
 func BenchmarkServer(b *testing.B) {
 	u, _ := url.Parse("/?Action=GetEcho&Version=2020-01-01&name=alice")