diff --git a/src/Directory.Build.props b/src/Directory.Build.props
index 1fb597706..b471c3d28 100644
--- a/src/Directory.Build.props
+++ b/src/Directory.Build.props
@@ -2,7 +2,7 @@
 <Project>
   <PropertyGroup>
     <NoWarn>CS1591;CS0649;xUnit1026;xUnit1013;CS1573;VerifyTestsProjectDir;VerifySetParameters</NoWarn>
-    <Version>23.5.2</Version>
+    <Version>23.6.0</Version>
     <ImplicitUsings>enable</ImplicitUsings>
     <LangVersion>preview</LangVersion>
     <AssemblyVersion>1.0.0</AssemblyVersion>
diff --git a/src/Verify/Serialization/VerifierSettings_SerializationMaps.cs b/src/Verify/Serialization/VerifierSettings_SerializationMaps.cs
index 35f40eb96..e8ac3bcad 100644
--- a/src/Verify/Serialization/VerifierSettings_SerializationMaps.cs
+++ b/src/Verify/Serialization/VerifierSettings_SerializationMaps.cs
@@ -8,13 +8,13 @@ public static void AddExtraSettings(Action<JsonSerializerSettings> action)
         serialization.AddExtraSettings(action);
     }
 
-    public static void AddExtraDateFormat(string format)
+    public static void AddExtraDateFormat([StringSyntax(StringSyntaxAttribute.DateOnlyFormat)] string format)
     {
         InnerVerifier.ThrowIfVerifyHasBeenRun();
         SerializationSettings.dateFormats.Add(format);
     }
 
-    public static void AddExtraTimeFormat(string format)
+    public static void AddExtraTimeFormat([StringSyntax(StringSyntaxAttribute.TimeOnlyFormat)] string format)
     {
         InnerVerifier.ThrowIfVerifyHasBeenRun();
         SerializationSettings.timeFormats.Add(format);
@@ -24,7 +24,7 @@ public static void AddExtraTimeFormat(string format)
     public static void AddExtraDatetimeFormat(string format) =>
         AddExtraDateTimeFormat(format);
 
-    public static void AddExtraDateTimeFormat(string format)
+    public static void AddExtraDateTimeFormat([StringSyntax(StringSyntaxAttribute.DateTimeFormat)] string format)
     {
         InnerVerifier.ThrowIfVerifyHasBeenRun();
         SerializationSettings.dateTimeFormats.Add(format);
@@ -34,7 +34,7 @@ public static void AddExtraDateTimeFormat(string format)
     public static void AddExtraDatetimeOffsetFormat(string format) =>
         AddExtraDateTimeOffsetFormat(format);
 
-    public static void AddExtraDateTimeOffsetFormat(string format)
+    public static void AddExtraDateTimeOffsetFormat([StringSyntax(StringSyntaxAttribute.DateTimeFormat)] string format)
     {
         InnerVerifier.ThrowIfVerifyHasBeenRun();
         SerializationSettings.dateTimeOffsetFormats.Add(format);