diff --git a/nixos/modules/services/monitoring/grafana.nix b/nixos/modules/services/monitoring/grafana.nix
index c2f6b585d49..bf1084eecc3 100644
--- a/nixos/modules/services/monitoring/grafana.nix
+++ b/nixos/modules/services/monitoring/grafana.nix
@@ -503,12 +503,12 @@ in {
         message = "Cannot set both adminPassword and adminPasswordFile";
       }
       {
-        assertion = cfg.security.secretKeyFile != opt.security.secretKeyFile.default -> cfg.security.secretKeyFile == null;
+        assertion = cfg.security.secretKey != opt.security.secretKey.default -> cfg.security.secretKeyFile == null;
         message = "Cannot set both secretKey and secretKeyFile";
       }
       {
         assertion = cfg.smtp.password != opt.smtp.password.default -> cfg.smtp.passwordFile == null;
-        message = "Cannot set both password and secretKeyFile";
+        message = "Cannot set both password and passwordFile";
       }
     ];