diff --git a/main_test.go b/main_test.go
index 47d6c7a..d1a8b68 100644
--- a/main_test.go
+++ b/main_test.go
@@ -2,6 +2,7 @@ package main
 
 import (
 	"encoding/json"
+	"fmt"
 	"io"
 	"log"
 	"net/http"
@@ -133,6 +134,12 @@ func TestApi(t *testing.T) {
 func TestValidateEndpoint(t *testing.T) {
 	validYml := loadTestdata(t, "valid.publiccode.yml")
 	invalidYml := loadTestdata(t, "invalid.publiccode.yml")
+	externalChecksYml := strings.Replace(
+		validYml,
+		"https://github.com/example/project.git",
+		"http://127.0.0.1/repository.git",
+		1,
+	)
 
 	tests := []TestCase{
 		{
@@ -167,6 +174,32 @@ func TestValidateEndpoint(t *testing.T) {
 				assert.NotNil(t, response["normalized"])
 			},
 		},
+		{
+			description:         "validate: external checks disabled",
+			query:               "QUERY /v1/validate",
+			body:                externalChecksYml,
+			expectedCode:        200,
+			expectedContentType: "application/json; charset=utf-8",
+			validateFunc: func(t *testing.T, response map[string]any) {
+				assert.Equal(t, true, response["valid"])
+				assert.Empty(t, response["results"])
+			},
+		},
+		{
+			description:         "validate: external checks enabled",
+			query:               "QUERY /v1/validate?external-checks=true",
+			body:                externalChecksYml,
+			expectedCode:        200,
+			expectedContentType: "application/json; charset=utf-8",
+			validateFunc: func(t *testing.T, response map[string]any) {
+				assert.Equal(t, false, response["valid"])
+				results, ok := response["results"].([]any)
+				assert.True(t, ok)
+				assert.NotEmpty(t, results)
+				assert.Contains(t, fmt.Sprint(results), "non-public")
+				assert.Nil(t, response["normalized"])
+			},
+		},
 		{
 			description:         "validate: invalid file",
 			query:               "QUERY /v1/validate",
diff --git a/testdata/invalid.publiccode.yml b/testdata/invalid.publiccode.yml
index 63daa3c..c050635 100644
--- a/testdata/invalid.publiccode.yml
+++ b/testdata/invalid.publiccode.yml
@@ -1,7 +1,7 @@
 publiccodeYmlVersion: "0"
 
 name: Medusa
-url: "https://github.com/italia/developers.italia.it.git"
+url: "https://github.com/example/project.git"
 
 platforms:
   - web
diff --git a/testdata/valid.publiccode.yml b/testdata/valid.publiccode.yml
index 712ebe3..f197344 100644
--- a/testdata/valid.publiccode.yml
+++ b/testdata/valid.publiccode.yml
@@ -1,7 +1,7 @@
 publiccodeYmlVersion: "0"
 
 name: Medusa
-url: "https://github.com/italia/developers.italia.it.git"
+url: "https://github.com/example/project.git"
 
 platforms:
   - web