diff --git a/pkgs/pkgs-lib/tests/formats.nix b/pkgs/pkgs-lib/tests/formats.nix
index 5f6f3b93e280..1c6f741353fa 100644
--- a/pkgs/pkgs-lib/tests/formats.nix
+++ b/pkgs/pkgs-lib/tests/formats.nix
@@ -118,7 +118,7 @@ in runBuildTests {
     '';
   };
 
-  yamlAtoms = shouldPass {
+  yaml_1_1Atoms = shouldPass {
     format = formats.yaml {};
     input = {
       null = null;
@@ -129,6 +129,8 @@ in runBuildTests {
       attrs.foo = null;
       list = [ null null ];
       path = ./formats.nix;
+      no = "no";
+      time = "22:30:00";
     };
     expected = ''
       attrs:
@@ -138,9 +140,11 @@ in runBuildTests {
       list:
       - null
       - null
+      'no': 'no'
       'null': null
       path: ${./formats.nix}
       str: foo
+      time: '22:30:00'
       'true': true
     '';
   };