diff --git a/packages/grafana-prometheus/src/querybuilder/components/MetricCombobox.tsx b/packages/grafana-prometheus/src/querybuilder/components/MetricCombobox.tsx
index 26b55f30087..f5c3c4808f5 100644
--- a/packages/grafana-prometheus/src/querybuilder/components/MetricCombobox.tsx
+++ b/packages/grafana-prometheus/src/querybuilder/components/MetricCombobox.tsx
@@ -95,6 +95,7 @@ export function MetricCombobox({
           options={loadOptions}
           value={query.metric}
           onChange={onComboboxChange}
+          createCustomValue
         />
 
         {metricsExplorerEnabled ? (