diff --git a/public/app/plugins/datasource/prometheus/querybuilder/components/MetricsLabelsSection.tsx b/public/app/plugins/datasource/prometheus/querybuilder/components/MetricsLabelsSection.tsx
index 504990d947a..f6b4f26f47e 100644
--- a/public/app/plugins/datasource/prometheus/querybuilder/components/MetricsLabelsSection.tsx
+++ b/public/app/plugins/datasource/prometheus/querybuilder/components/MetricsLabelsSection.tsx
@@ -60,7 +60,6 @@ export function MetricsLabelsSection({
   const onGetLabelNames = async (forLabel: Partial<QueryBuilderLabelFilter>): Promise<SelectableValue[]> => {
     // If no metric we need to use a different method
     if (!query.metric) {
-      // FIXME pass timeRange to fetchLabels method
       await datasource.languageProvider.fetchLabels();
       return datasource.languageProvider.getLabelKeys().map((k) => ({ value: k }));
     }
diff --git a/public/app/plugins/datasource/prometheus/querybuilder/components/PromQueryBuilderContainer.tsx b/public/app/plugins/datasource/prometheus/querybuilder/components/PromQueryBuilderContainer.tsx
index 70786203ead..fe641f96550 100644
--- a/public/app/plugins/datasource/prometheus/querybuilder/components/PromQueryBuilderContainer.tsx
+++ b/public/app/plugins/datasource/prometheus/querybuilder/components/PromQueryBuilderContainer.tsx
@@ -51,6 +51,10 @@ export function PromQueryBuilderContainer(props: Props) {
     }
   }, [query]);
 
+  useEffect(() => {
+    datasource.languageProvider.start(data?.timeRange);
+  }, [data?.timeRange, datasource.languageProvider]);
+
   const onVisQueryChange = (visQuery: PromVisualQuery) => {
     const expr = promQueryModeller.renderQuery(visQuery);
     dispatch(visualQueryChange({ visQuery, expr }));
@@ -77,7 +81,7 @@ export function PromQueryBuilderContainer(props: Props) {
         data={data}
         showExplain={showExplain}
       />
-      {<QueryPreview query={query.expr} />}
+      <QueryPreview query={query.expr} />
     </>
   );
 }