diff --git a/backend/controller/ingress/ingress.go b/backend/controller/ingress/ingress.go
index 8454900ecb..ea8704c54a 100644
--- a/backend/controller/ingress/ingress.go
+++ b/backend/controller/ingress/ingress.go
@@ -122,6 +122,11 @@ func ValidateAndExtractRequestBody(route *dal.IngressRoute, r *http.Request, sch
 		requestMap["headers"] = r.Header
 		requestMap["body"] = bodyMap
 
+		requestMap, err = transformAliasedFields(request, sch, requestMap)
+		if err != nil {
+			return nil, err
+		}
+
 		err = validateRequestMap(request, []string{request.String()}, requestMap, sch)
 		if err != nil {
 			return nil, err
@@ -197,7 +202,6 @@ func buildRequest(route *dal.IngressRoute, r *http.Request, dataRef *schema.Data
 			requestMap[key] = value
 		}
 	}
-	transformAliasedFields(dataRef, sch, requestMap)
 
 	return requestMap, nil
 }
@@ -452,12 +456,32 @@ func hasInvalidQueryChars(s string) bool {
 	return strings.ContainsAny(s, "{}[]|\\^`")
 }
 
-func transformAliasedFields(dataRef *schema.DataRef, sch *schema.Schema, request map[string]any) {
+func transformAliasedFields(dataRef *schema.DataRef, sch *schema.Schema, request map[string]any) (map[string]any, error) {
 	data := sch.ResolveDataRef(dataRef)
+	if len(dataRef.TypeParameters) > 0 {
+		var err error
+		data, err = data.Monomorphise(dataRef.TypeParameters...)
+		if err != nil {
+			return nil, err
+		}
+	}
+
 	for _, field := range data.Fields {
 		if _, ok := request[field.Name]; !ok && field.Alias != "" {
 			request[field.Name] = request[field.Alias]
 			delete(request, field.Alias)
 		}
+
+		if d, ok := field.Type.(*schema.DataRef); ok {
+			if _, found := request[field.Name]; found {
+				rMap, err := transformAliasedFields(d, sch, request[field.Name].(map[string]any))
+				if err != nil {
+					return nil, err
+				}
+				request[field.Name] = rMap
+			}
+		}
 	}
+
+	return request, nil
 }
diff --git a/examples/kotlin/ftl-module-echo/src/main/kotlin/ftl/echo/Echo.kt b/examples/kotlin/ftl-module-echo/src/main/kotlin/ftl/echo/Echo.kt
index 96716f9cf0..dc5d453725 100644
--- a/examples/kotlin/ftl-module-echo/src/main/kotlin/ftl/echo/Echo.kt
+++ b/examples/kotlin/ftl-module-echo/src/main/kotlin/ftl/echo/Echo.kt
@@ -6,19 +6,18 @@ import xyz.block.ftl.Context
 import xyz.block.ftl.Ingress
 import xyz.block.ftl.Method
 import xyz.block.ftl.Verb
-import xyz.block.ftl.Alias
 
 class InvalidInput(val field: String) : Exception()
 
-data class EchoRequest(val name: String?, @Alias("m") val metadata: String)
+data class EchoRequest(val name: String?)
 data class EchoResponse(val message: String)
 
 class Echo {
   @Throws(InvalidInput::class)
   @Verb
-  @Ingress(Method.POST, "/echo")
+  @Ingress(Method.GET, "/echo")
   fun echo(context: Context, req: EchoRequest): EchoResponse {
     val response = context.call(TimeModuleClient::time, TimeRequest)
-    return EchoResponse(message = "Hello, ${req.name ?: "anonymous"}! The time is ${response.time}. Metadata: ${req.metadata}")
+    return EchoResponse(message = "Hello, ${req.name ?: "anonymous"}! The time is ${response.time}.")
   }
 }
diff --git a/integration/integration_test.go b/integration/integration_test.go
index 9c3bc2ccea..65f6ed2da2 100644
--- a/integration/integration_test.go
+++ b/integration/integration_test.go
@@ -61,7 +61,7 @@ func TestIntegration(t *testing.T) {
 			deploymentExists("echo"),
 		}},
 		{name: "CallEchoKotlin", assertions: assertions{
-			call("echo", "echo", obj{"name": "Alice", "metadata": "hi"}, func(t testing.TB, resp obj) {
+			call("echo", "echo", obj{"name": "Alice"}, func(t testing.TB, resp obj) {
 				message, ok := resp["message"].(string)
 				assert.True(t, ok, "message is not a string")
 				assert.True(t, regexp.MustCompile(`^Hello, Alice!`).MatchString(message), "%q does not match %q", message, `^Hello, Alice!`)