diff --git a/src/BUTR.NativeAOT.Shared/SafeDataMallocHandle.cs b/src/BUTR.NativeAOT.Shared/SafeDataMallocHandle.cs
index 6b60ae6..6f0c9da 100644
--- a/src/BUTR.NativeAOT.Shared/SafeDataMallocHandle.cs
+++ b/src/BUTR.NativeAOT.Shared/SafeDataMallocHandle.cs
@@ -35,6 +35,8 @@ namespace BUTR.NativeAOT.Shared
 
     internal sealed unsafe class SafeDataMallocHandle : SafeHandleZeroOrMinusOneIsInvalid
     {
+        public static SafeDataMallocHandle Create(byte* ptr, int length, bool isOwner) => new(ptr, length, isOwner);
+
         public static implicit operator param_data*(SafeDataMallocHandle handle) => (param_data*) handle.handle.ToPointer();
         public static implicit operator byte*(SafeDataMallocHandle handle) => (byte*) handle.handle.ToPointer();
 
diff --git a/src/BUTR.NativeAOT.Shared/SafeStringMallocHandle.cs b/src/BUTR.NativeAOT.Shared/SafeStringMallocHandle.cs
index a601f01..22aa056 100644
--- a/src/BUTR.NativeAOT.Shared/SafeStringMallocHandle.cs
+++ b/src/BUTR.NativeAOT.Shared/SafeStringMallocHandle.cs
@@ -35,6 +35,8 @@ namespace BUTR.NativeAOT.Shared
 
     internal sealed unsafe class SafeStringMallocHandle : SafeHandleZeroOrMinusOneIsInvalid
     {
+        public static SafeStringMallocHandle Create(char* ptr, bool isOwner) => new(ptr, isOwner);
+
         public static implicit operator param_string*(SafeStringMallocHandle handle) => (param_string*) handle.handle.ToPointer();
         public static implicit operator param_json*(SafeStringMallocHandle handle) => (param_json*) handle.handle.ToPointer();
         public static implicit operator char*(SafeStringMallocHandle handle) => (char*) handle.handle.ToPointer();
diff --git a/src/BUTR.NativeAOT.Shared/SafeStructMallocHandle.cs b/src/BUTR.NativeAOT.Shared/SafeStructMallocHandle.cs
index 9c0cde2..253aa73 100644
--- a/src/BUTR.NativeAOT.Shared/SafeStructMallocHandle.cs
+++ b/src/BUTR.NativeAOT.Shared/SafeStructMallocHandle.cs
@@ -97,7 +97,7 @@ public SafeStringMallocHandle ValueAsString()
             throw new NativeCallException(new string(hError));
         }
 
-        public TValue? ValueAsJson<TValue>(JsonTypeInfo<TValue> jsonTypeInfo, [CallerMemberName] string? caller = null) where TValue : class
+        public TValue? ValueAsJson<TValue>(JsonTypeInfo<TValue?> jsonTypeInfo, [CallerMemberName] string? caller = null) where TValue : class
         {
             if (typeof(TStruct) != typeof(return_value_json))
                 throw new Exception();
@@ -235,7 +235,7 @@ public void SetAsString(TaskCompletionSource<string?> tcs)
             tcs.TrySetException(new NativeCallException(new string(hError)));
         }
 
-        public void SetAsJson<TValue>(TaskCompletionSource<TValue?> tcs, JsonTypeInfo<TValue> jsonTypeInfo, [CallerMemberName] string? caller = null) where TValue : class
+        public void SetAsJson<TValue>(TaskCompletionSource<TValue?> tcs, JsonTypeInfo<TValue?> jsonTypeInfo, [CallerMemberName] string? caller = null) where TValue : class
         {
             if (typeof(TStruct) != typeof(return_value_json))
             {
diff --git a/src/BUTR.NativeAOT.Shared/Utils.cs b/src/BUTR.NativeAOT.Shared/Utils.cs
index 4aac294..ef22159 100644
--- a/src/BUTR.NativeAOT.Shared/Utils.cs
+++ b/src/BUTR.NativeAOT.Shared/Utils.cs
@@ -47,14 +47,14 @@ public static SafeStringMallocHandle SerializeJsonCopy<TValue>(TValue value, Jso
         public static string SerializeJson<TValue>(TValue? value, JsonTypeInfo<TValue> jsonTypeInfo)
             where TValue : class => value is null ? string.Empty : JsonSerializer.Serialize(value, jsonTypeInfo);
 
-        public static TValue? DeserializeJson<TValue>(SafeStringMallocHandle json, JsonTypeInfo<TValue> jsonTypeInfo, [CallerMemberName] string? caller = null)
+        public static TValue? DeserializeJson<TValue>(SafeStringMallocHandle json, JsonTypeInfo<TValue?> jsonTypeInfo, [CallerMemberName] string? caller = null)
             where TValue : class => json.IsInvalid ? null : DeserializeJson(json.ToSpan(), jsonTypeInfo, caller);
 
         [return: NotNullIfNotNull(nameof(json))]
-        public static unsafe TValue? DeserializeJson<TValue>(param_json* json, JsonTypeInfo<TValue> jsonTypeInfo, [CallerMemberName] string? caller = null)
+        public static unsafe TValue? DeserializeJson<TValue>(param_json* json, JsonTypeInfo<TValue?> jsonTypeInfo, [CallerMemberName] string? caller = null)
             where TValue : class => json is null ? null : DeserializeJson(param_json.ToSpan(json), jsonTypeInfo, caller);
 
-        private static TValue? DeserializeJson<TValue>([StringSyntax(StringSyntaxAttribute.Json)] ReadOnlySpan<char> json, JsonTypeInfo<TValue> jsonTypeInfo, [CallerMemberName] string? caller = null)
+        private static TValue? DeserializeJson<TValue>([StringSyntax(StringSyntaxAttribute.Json)] ReadOnlySpan<char> json, JsonTypeInfo<TValue?> jsonTypeInfo, [CallerMemberName] string? caller = null)
         {
             try
             {
@@ -71,7 +71,7 @@ public static unsafe SafeDataMallocHandle Copy(in ReadOnlySpan<byte> data, bool
         {
             var dst = (byte*) Allocator.Alloc(new UIntPtr((uint) data.Length));
             data.CopyTo(new Span<byte>(dst, data.Length));
-            return new(dst, data.Length, isOwner);
+            return SafeDataMallocHandle.Create(dst, data.Length, isOwner);
         }
 
         public static unsafe SafeStringMallocHandle Copy(in ReadOnlySpan<char> str, bool isOwner)
@@ -80,7 +80,7 @@ public static unsafe SafeStringMallocHandle Copy(in ReadOnlySpan<char> str, bool
             var dst = (char*) Allocator.Alloc(new UIntPtr(size));
             str.CopyTo(new Span<char>(dst, str.Length));
             dst[str.Length] = '\0';
-            return new(dst, isOwner);
+            return SafeStringMallocHandle.Create(dst, isOwner);
         }
 
         public static unsafe SafeStructMallocHandle<TValue> Create<TValue>(TValue value, bool isOwner) where TValue : unmanaged