diff --git a/src/runtime/clrobject.cs b/src/runtime/clrobject.cs
index 472e5dcbb..9f14c900a 100644
--- a/src/runtime/clrobject.cs
+++ b/src/runtime/clrobject.cs
@@ -11,7 +11,7 @@ internal CLRObject(object ob, IntPtr tp)
         {
             IntPtr py = Runtime.PyType_GenericAlloc(tp, 0);
 
-            var flags = (int)Marshal.ReadIntPtr(tp, TypeOffset.tp_flags);
+            var flags = (long)Marshal.ReadIntPtr(tp, TypeOffset.tp_flags);
             if ((flags & TypeFlags.Subclass) != 0)
             {
                 IntPtr dict = Marshal.ReadIntPtr(py, ObjectOffset.DictOffset(tp));
diff --git a/src/runtime/debughelper.cs b/src/runtime/debughelper.cs
index 777a61e35..f215a803a 100644
--- a/src/runtime/debughelper.cs
+++ b/src/runtime/debughelper.cs
@@ -89,7 +89,7 @@ internal static void DumpType(IntPtr type)
         internal static void DumpInst(IntPtr ob)
         {
             IntPtr tp = Runtime.PyObject_TYPE(ob);
-            var sz = (int)Marshal.ReadIntPtr(tp, TypeOffset.tp_basicsize);
+            var sz = (long)Marshal.ReadIntPtr(tp, TypeOffset.tp_basicsize);
 
             for (var i = 0; i < sz; i += IntPtr.Size)
             {
diff --git a/src/runtime/managedtype.cs b/src/runtime/managedtype.cs
index 9ee8d223b..842ef6a83 100644
--- a/src/runtime/managedtype.cs
+++ b/src/runtime/managedtype.cs
@@ -28,7 +28,7 @@ internal static ManagedType GetManagedObject(IntPtr ob)
                     tp = ob;
                 }
 
-                var flags = (int)Marshal.ReadIntPtr(tp, TypeOffset.tp_flags);
+                var flags = (long)Marshal.ReadIntPtr(tp, TypeOffset.tp_flags);
                 if ((flags & TypeFlags.Managed) != 0)
                 {
                     IntPtr op = tp == ob
@@ -63,7 +63,7 @@ internal static bool IsManagedType(IntPtr ob)
                     tp = ob;
                 }
 
-                var flags = (int)Marshal.ReadIntPtr(tp, TypeOffset.tp_flags);
+                var flags = (long)Marshal.ReadIntPtr(tp, TypeOffset.tp_flags);
                 if ((flags & TypeFlags.Managed) != 0)
                 {
                     return true;
diff --git a/src/runtime/metatype.cs b/src/runtime/metatype.cs
index bfb71e26d..df896c985 100644
--- a/src/runtime/metatype.cs
+++ b/src/runtime/metatype.cs
@@ -247,7 +247,7 @@ public static void tp_dealloc(IntPtr tp)
         {
             // Fix this when we dont cheat on the handle for subclasses!
 
-            var flags = (int)Marshal.ReadIntPtr(tp, TypeOffset.tp_flags);
+            var flags = (long)Marshal.ReadIntPtr(tp, TypeOffset.tp_flags);
             if ((flags & TypeFlags.Subclass) == 0)
             {
                 IntPtr gc = Marshal.ReadIntPtr(tp, TypeOffset.magic());