diff --git a/src/GraphQL.DI/DIObjectGraphType.cs b/src/GraphQL.DI/DIObjectGraphType.cs
index 24fe23b..b2d3d83 100644
--- a/src/GraphQL.DI/DIObjectGraphType.cs
+++ b/src/GraphQL.DI/DIObjectGraphType.cs
@@ -266,7 +266,7 @@ protected virtual bool GetNullability(MethodInfo method)
                 nullable = (Nullability)(byte)attribute.ConstructorArguments[0].Value;
             }
 
-            var nullabilityBytes = attribute?.ConstructorArguments[0].Value as byte[];
+            var nullabilityBytes = attribute?.ConstructorArguments[0].Value as IList<CustomAttributeTypedArgument>;
             var index = 0;
             nullable = Consider(method.ReturnType);
             return nullable != Nullability.NonNullable;
@@ -278,7 +278,7 @@ Nullability Consider(Type t)
                     return Nullability.Nullable;
                 if (t.IsValueType)
                     return Nullability.NonNullable;
-                if ((nullabilityBytes != null && nullabilityBytes[index] == (byte)Nullability.Nullable) || (nullabilityBytes == null && nullable == Nullability.Nullable))
+                if ((nullabilityBytes != null && (byte)nullabilityBytes[index].Value == (byte)Nullability.Nullable) || (nullabilityBytes == null && nullable == Nullability.Nullable))
                     return Nullability.Nullable;
                 if (g == typeof(IDataLoaderResult<>) || g == typeof(Task<>)) {
                     index++;
@@ -287,7 +287,7 @@ Nullability Consider(Type t)
                 if (t == typeof(IDataLoaderResult))
                     return Nullability.Nullable;
                 if (nullabilityBytes != null)
-                    return (Nullability)nullabilityBytes[index];
+                    return (Nullability)(byte)nullabilityBytes[index].Value;
                 return nullable;
             }
         }
diff --git a/src/Tests/DIObjectGraphTypeTests/Nullable.cs b/src/Tests/DIObjectGraphTypeTests/Nullable.cs
index 54ae8fb..f75897f 100644
--- a/src/Tests/DIObjectGraphTypeTests/Nullable.cs
+++ b/src/Tests/DIObjectGraphTypeTests/Nullable.cs
@@ -32,6 +32,7 @@ public class Nullable
         [InlineData(typeof(NullableClass15), null, null)]
         [InlineData(typeof(NullableClass16), 1, 0)]
         [InlineData(typeof(NullableClass16.NestedClass1), null, 0)]
+        [InlineData(typeof(NullableClass17), 1, 0)]
         public void VerifyTestClass(Type type, int? nullableContext, int? nullable)
         {
             var actualHasNullableContext = type.CustomAttributes.FirstOrDefault(
@@ -100,8 +101,13 @@ public void VerifyTestClass(Type type, int? nullableContext, int? nullable)
         [InlineData(typeof(NullableClass15), "Field4", false, true)]
         [InlineData(typeof(NullableClass16), "Field1", false, false)]
         [InlineData(typeof(NullableClass16), "Field2", false, false)]
+        [InlineData(typeof(NullableClass16), "Field3", false, true)]
         [InlineData(typeof(NullableClass16.NestedClass1), "Field1", false, false)]
         [InlineData(typeof(NullableClass16.NestedClass1), "Field2", false, false)]
+        [InlineData(typeof(NullableClass16.NestedClass1), "Field3", false, true)]
+        [InlineData(typeof(NullableClass17), "Field1", false, false)]
+        [InlineData(typeof(NullableClass17), "Field2", false, false)]
+        [InlineData(typeof(NullableClass17), "Field3", true, false)]
         public void VerifyTestMethod(Type type, string methodName, bool hasNullable, bool hasNullableContext)
         {
             var method = type.GetMethod(methodName);
@@ -189,8 +195,13 @@ public void VerifyTestArgument(Type type, string methodName, string argumentName
         [InlineData(typeof(NullableClass15), "Field4", true)]
         [InlineData(typeof(NullableClass16), "Field1", false)]
         [InlineData(typeof(NullableClass16), "Field2", false)]
+        [InlineData(typeof(NullableClass16), "Field3", true)]
         [InlineData(typeof(NullableClass16.NestedClass1), "Field1", false)]
         [InlineData(typeof(NullableClass16.NestedClass1), "Field2", false)]
+        [InlineData(typeof(NullableClass16.NestedClass1), "Field3", true)]
+        [InlineData(typeof(NullableClass17), "Field1", false)]
+        [InlineData(typeof(NullableClass17), "Field2", false)]
+        [InlineData(typeof(NullableClass17), "Field3", true)]
         public void Method(Type type, string methodName, bool expected)
         {
             var method = type.GetMethod(methodName);
diff --git a/src/Tests/NullabilityTestClasses.cs b/src/Tests/NullabilityTestClasses.cs
index 6f75e8e..6b23448 100644
--- a/src/Tests/NullabilityTestClasses.cs
+++ b/src/Tests/NullabilityTestClasses.cs
@@ -114,11 +114,20 @@ public class NullableClass16
     {
         public static string Field1() => "test";
         public static string Field2() => "test";
+        public static string? Field3() => "test";
 
         public class NestedClass1
         {
             public static string Field1() => "test";
             public static string Field2() => "test";
+            public static string? Field3() => "test";
         }
     }
+
+    public class NullableClass17
+    {
+        public static Task<string> Field1() => null!;
+        public static Task<string> Field2() => null!;
+        public static Task<string?> Field3() => null!;
+    }
 }