diff --git a/Octokit.Tests.Conventions/Exception/MissingPublicParameterlessCtorException.cs b/Octokit.Tests.Conventions/Exception/MissingPublicParameterlessCtorException.cs
new file mode 100644
index 00000000..806c70d0
--- /dev/null
+++ b/Octokit.Tests.Conventions/Exception/MissingPublicParameterlessCtorException.cs
@@ -0,0 +1,11 @@
+using System;
+
+namespace Octokit.Tests.Conventions
+{
+    public class MissingPublicParameterlessCtorException : Exception
+    {
+        public MissingPublicParameterlessCtorException(Type modelType)
+            : base(string.Format("Model type '{0}' is missing a Public Parameterless Constructor required by SimpleJson Deserializer.", modelType.FullName))
+        { }
+    }
+}
\ No newline at end of file
diff --git a/Octokit.Tests.Conventions/ModelTests.cs b/Octokit.Tests.Conventions/ModelTests.cs
index 1d3f5e16..7da1fcec 100644
--- a/Octokit.Tests.Conventions/ModelTests.cs
+++ b/Octokit.Tests.Conventions/ModelTests.cs
@@ -37,6 +37,18 @@ namespace Octokit.Tests.Conventions
             }
         }
 
+        [Theory]
+        [MemberData("ResponseModelTypes")]
+        public void AllResponseModelsHavePublicParameterlessCtors(Type modelType)
+        {
+            var ctor = modelType.GetConstructor(Type.EmptyTypes);
+
+            if (ctor == null || !ctor.IsPublic)
+            {
+                throw new MissingPublicParameterlessCtorException(modelType);
+            }
+        }
+
         [Theory]
         [MemberData("ResponseModelTypes")]
         public void ResponseModelsHaveGetterOnlyProperties(Type modelType)
diff --git a/Octokit.Tests.Conventions/Octokit.Tests.Conventions.csproj b/Octokit.Tests.Conventions/Octokit.Tests.Conventions.csproj
index e06a67b8..412724b7 100644
--- a/Octokit.Tests.Conventions/Octokit.Tests.Conventions.csproj
+++ b/Octokit.Tests.Conventions/Octokit.Tests.Conventions.csproj
@@ -67,6 +67,7 @@
     <Compile Include="Exception\MissingClientConstructorTestClassException.cs" />
     <Compile Include="Exception\MissingClientConstructorTestMethodException.cs" />
     <Compile Include="Exception\MissingDebuggerDisplayAttributeException.cs" />
+    <Compile Include="Exception\MissingPublicParameterlessCtorException.cs" />
     <Compile Include="Exception\MissingDebuggerDisplayPropertyException.cs" />
     <Compile Include="Exception\MutableModelPropertiesException.cs" />
     <Compile Include="Exception\PaginationGetAllMethodNameMismatchException.cs" />
diff --git a/Octokit/Models/Response/PunchCard.cs b/Octokit/Models/Response/PunchCard.cs
index 4fdb5d79..02c0bdec 100644
--- a/Octokit/Models/Response/PunchCard.cs
+++ b/Octokit/Models/Response/PunchCard.cs
@@ -10,6 +10,9 @@ namespace Octokit
     [DebuggerDisplay("{DebuggerDisplay,nq}")]
     public class PunchCard
     {
+        public PunchCard()
+        { }
+
         public PunchCard(IEnumerable<IList<int>> punchCardData)
         {
             Ensure.ArgumentNotNull(punchCardData, "punchCardData");
diff --git a/Octokit/Models/Response/RepositoryLanguage.cs b/Octokit/Models/Response/RepositoryLanguage.cs
index 44fd9c7a..c1d762eb 100644
--- a/Octokit/Models/Response/RepositoryLanguage.cs
+++ b/Octokit/Models/Response/RepositoryLanguage.cs
@@ -7,6 +7,9 @@ namespace Octokit
     [DebuggerDisplay("{DebuggerDisplay,nq}")]
     public class RepositoryLanguage
     {
+        public RepositoryLanguage()
+        { }
+
         public RepositoryLanguage(string name, long numberOfBytes)
         {
             Name = name;