diff --git a/nixos/modules/services/monitoring/prometheus/exporters/nginx.nix b/nixos/modules/services/monitoring/prometheus/exporters/nginx.nix
index 39054c2b73dd..431dd8b4ead7 100644
--- a/nixos/modules/services/monitoring/prometheus/exporters/nginx.nix
+++ b/nixos/modules/services/monitoring/prometheus/exporters/nginx.nix
@@ -39,7 +39,7 @@ in
           --nginx.scrape_uri '${cfg.scrapeUri}' \
           --telemetry.address ${cfg.listenAddress}:${toString cfg.port} \
           --telemetry.endpoint ${cfg.telemetryEndpoint} \
-          --insecure ${cfg.insecure} \
+          --insecure ${toString cfg.insecure} \
           ${concatStringsSep " \\\n  " cfg.extraFlags}
       '';
     };