diff --git a/public/app/plugins/datasource/graphite/datasource.ts b/public/app/plugins/datasource/graphite/datasource.ts
index efb107e3b16..84084a0609a 100644
--- a/public/app/plugins/datasource/graphite/datasource.ts
+++ b/public/app/plugins/datasource/graphite/datasource.ts
@@ -228,7 +228,7 @@ export function GraphiteDatasource(instanceSettings, $q, backendSrv, templateSrv
     }
 
     function nestedSeriesRegexReplacer(match, g1) {
-      return targets[g1];
+      return targets[g1] || match;
     }
 
     for (i = 0; i < options.targets.length; i++) {