diff --git a/extensions/json/server/src/test/schema.test.ts b/extensions/json/server/src/test/schema.test.ts
index a97c882577244022eb143289092854de2dce6d32..6a79c6d98afc29741e8caecddf91573f042e8087 100644
--- a/extensions/json/server/src/test/schema.test.ts
+++ b/extensions/json/server/src/test/schema.test.ts
@@ -367,7 +367,7 @@ suite('JSON Schema', () => {
 			service.clearExternalSchemas();
 			return service.getSchemaForResource('main.bar', null).then(resolvedSchema => {
 				assert.equal(resolvedSchema.errors.length, 1);
-				assert.ok(resolvedSchema.errors[0].indexOf("Problems loading reference 'http://myschemastore/myschemafoo'") === 0);
+				assert.equal(resolvedSchema.errors[0], "Problems loading reference 'http://myschemastore/myschemafoo': Unable to load schema from 'http://myschemastore/myschemafoo': Not Found. The requested location could not be found.");
 
 				service.clearExternalSchemas();
 				service.registerExternalSchema(id2, null, schema2);