diff --git a/lib/datasource/docker.js b/lib/datasource/docker.js
index 650f1f4b20e3cbb3e64b059c96cb4671b13c1574..32a13ccc9acfa4467dc2387f4a58a352fe2eb176 100644
--- a/lib/datasource/docker.js
+++ b/lib/datasource/docker.js
@@ -18,7 +18,7 @@ function massageRegistry(input) {
 }
 
 function getRepository(pkgName) {
-  return pkgName.includes('/') ? pkgName : `library/${pkgName}`;
+  return pkgName.includes('/') ? pkgName : `amd64/${pkgName}`;
 }
 
 async function getAuthHeaders(registry, repository) {