diff --git a/Src/Newtonsoft.Json.Tests/Converters/IsoDateTimeConverterTests.cs b/Src/Newtonsoft.Json.Tests/Converters/IsoDateTimeConverterTests.cs
index 942e2a69..40062de1 100644
--- a/Src/Newtonsoft.Json.Tests/Converters/IsoDateTimeConverterTests.cs
+++ b/Src/Newtonsoft.Json.Tests/Converters/IsoDateTimeConverterTests.cs
@@ -130,7 +130,11 @@ namespace Newtonsoft.Json.Tests.Converters
         [Test]
         public void SerializeFormattedDateTimeNewZealandCulture()
         {
-            IsoDateTimeConverter converter = new IsoDateTimeConverter() { DateTimeFormat = "F", Culture = CultureInfo.GetCultureInfo("en-NZ") };
+            CultureInfo culture = new CultureInfo("en-NZ");
+            culture.DateTimeFormat.AMDesignator = "a.m.";
+            culture.DateTimeFormat.PMDesignator = "p.m.";
+
+            IsoDateTimeConverter converter = new IsoDateTimeConverter() { DateTimeFormat = "F", Culture = culture };
 
             DateTime d = new DateTime(2000, 12, 15, 22, 11, 3, 0, DateTimeKind.Utc);
             string result;
diff --git a/Src/Newtonsoft.Json.Tests/JsonTextWriterTest.cs b/Src/Newtonsoft.Json.Tests/JsonTextWriterTest.cs
index 9724f1ef..248b9994 100644
--- a/Src/Newtonsoft.Json.Tests/JsonTextWriterTest.cs
+++ b/Src/Newtonsoft.Json.Tests/JsonTextWriterTest.cs
@@ -1237,11 +1237,15 @@ _____'propertyName': NaN,
         [Test]
         public void Culture()
         {
+            CultureInfo culture = new CultureInfo("en-NZ");
+            culture.DateTimeFormat.AMDesignator = "a.m.";
+            culture.DateTimeFormat.PMDesignator = "p.m.";
+
             StringWriter sw = new StringWriter();
             JsonTextWriter writer = new JsonTextWriter(sw);
             writer.Formatting = Formatting.Indented;
             writer.DateFormatString = "yyyy tt";
-            writer.Culture = new CultureInfo("en-NZ");
+            writer.Culture = culture;
             writer.QuoteChar = '\'';
 
             writer.WriteStartArray();
diff --git a/Src/Newtonsoft.Json.Tests/Serialization/JsonSerializerTest.cs b/Src/Newtonsoft.Json.Tests/Serialization/JsonSerializerTest.cs
index da130734..b80de6b1 100644
--- a/Src/Newtonsoft.Json.Tests/Serialization/JsonSerializerTest.cs
+++ b/Src/Newtonsoft.Json.Tests/Serialization/JsonSerializerTest.cs
@@ -8060,6 +8060,10 @@ Path '', line 1, position 1.");
         [Test]
         public void DateFormatString()
         {
+            CultureInfo culture = new CultureInfo("en-NZ");
+            culture.DateTimeFormat.AMDesignator = "a.m.";
+            culture.DateTimeFormat.PMDesignator = "p.m.";
+
             IList<object> dates = new List<object>
             {
                 new DateTime(2000, 12, 12, 12, 12, 12, DateTimeKind.Utc),
@@ -8069,7 +8073,7 @@ Path '', line 1, position 1.");
             string json = JsonConvert.SerializeObject(dates, Formatting.Indented, new JsonSerializerSettings
             {
                 DateFormatString = "yyyy tt",
-                Culture = new CultureInfo("en-NZ")
+                Culture = culture
             });
 
             StringAssert.AreEqual(@"[
@@ -8101,6 +8105,10 @@ Path '', line 1, position 1.");
         [Test]
         public void JsonSerializerDateFormatString()
         {
+            CultureInfo culture = new CultureInfo("en-NZ");
+            culture.DateTimeFormat.AMDesignator = "a.m.";
+            culture.DateTimeFormat.PMDesignator = "p.m.";
+
             IList<object> dates = new List<object>
             {
                 new DateTime(2000, 12, 12, 12, 12, 12, DateTimeKind.Utc),
@@ -8113,7 +8121,7 @@ Path '', line 1, position 1.");
             JsonSerializer serializer = JsonSerializer.Create(new JsonSerializerSettings
             {
                 DateFormatString = "yyyy tt",
-                Culture = new CultureInfo("en-NZ"),
+                Culture = culture,
                 Formatting = Formatting.Indented
             });
             serializer.Serialize(jsonWriter, dates);