diff --git a/services/grafana/default.nix b/services/grafana/default.nix
index a0dc7b4..0f801a4 100644
--- a/services/grafana/default.nix
+++ b/services/grafana/default.nix
@@ -37,6 +37,10 @@
     # Declarative datasources
     provision.datasources.settings = {
       apiVersion = 1;
+      # Remove old "Prometheus" datasource that was renamed to "Prometheus (monitoring01)"
+      deleteDatasources = [
+        { name = "Prometheus"; orgId = 1; }
+      ];
       datasources = [
         {
           name = "VictoriaMetrics";