diff --git a/src/coreclr/vm/appdomain.cpp b/src/coreclr/vm/appdomain.cpp
index f8436aca04d5b..decf569b90d3a 100644
--- a/src/coreclr/vm/appdomain.cpp
+++ b/src/coreclr/vm/appdomain.cpp
@@ -3965,7 +3965,7 @@ Assembly* AppDomain::RaiseTypeResolveEventThrowing(Assembly* pAssembly, LPCSTR s
     GCX_COOP();
 
     struct {
-        OBJECTREF AssemblyRef;
+        ASSEMBLYREF AssemblyRef;
         STRINGREF str;
     } gc;
     gc.AssemblyRef = NULL;
@@ -3974,7 +3974,7 @@ Assembly* AppDomain::RaiseTypeResolveEventThrowing(Assembly* pAssembly, LPCSTR s
     GCPROTECT_BEGIN(gc);
 
     if (pAssembly != NULL)
-        gc.AssemblyRef = pAssembly->GetExposedObject();
+        gc.AssemblyRef = (ASSEMBLYREF)pAssembly->GetExposedObject();
 
     MethodDescCallSite onTypeResolve(METHOD__ASSEMBLYLOADCONTEXT__ON_TYPE_RESOLVE);
 
@@ -3984,14 +3984,16 @@ Assembly* AppDomain::RaiseTypeResolveEventThrowing(Assembly* pAssembly, LPCSTR s
         ObjToArgSlot(gc.AssemblyRef),
         ObjToArgSlot(gc.str)
     };
-    ASSEMBLYREF ResultingAssemblyRef = (ASSEMBLYREF) onTypeResolve.Call_RetOBJECTREF(args);
+    gc.AssemblyRef = (ASSEMBLYREF) onTypeResolve.Call_RetOBJECTREF(args);
 
-    if (ResultingAssemblyRef != NULL)
+    if (gc.AssemblyRef != NULL)
     {
-        pResolvedAssembly = ResultingAssemblyRef->GetAssembly();
+        _ASSERTE(CoreLibBinder::IsClass(gc.AssemblyRef->GetMethodTable(), CLASS__ASSEMBLY));
+
+        pResolvedAssembly = gc.AssemblyRef->GetAssembly();
 
         if (pResultingAssemblyRef)
-            *pResultingAssemblyRef = ResultingAssemblyRef;
+            *pResultingAssemblyRef = gc.AssemblyRef;
         else
         {
             if (pResolvedAssembly->IsCollectible())
@@ -4023,7 +4025,7 @@ Assembly* AppDomain::RaiseResourceResolveEvent(Assembly* pAssembly, LPCSTR szNam
     GCX_COOP();
 
     struct {
-        OBJECTREF AssemblyRef;
+        ASSEMBLYREF AssemblyRef;
         STRINGREF str;
     } gc;
     gc.AssemblyRef = NULL;
@@ -4032,7 +4034,7 @@ Assembly* AppDomain::RaiseResourceResolveEvent(Assembly* pAssembly, LPCSTR szNam
     GCPROTECT_BEGIN(gc);
 
     if (pAssembly != NULL)
-        gc.AssemblyRef=pAssembly->GetExposedObject();
+        gc.AssemblyRef=(ASSEMBLYREF)pAssembly->GetExposedObject();
 
     MethodDescCallSite onResourceResolve(METHOD__ASSEMBLYLOADCONTEXT__ON_RESOURCE_RESOLVE);
     gc.str = StringObject::NewString(szName);
@@ -4041,10 +4043,12 @@ Assembly* AppDomain::RaiseResourceResolveEvent(Assembly* pAssembly, LPCSTR szNam
         ObjToArgSlot(gc.AssemblyRef),
         ObjToArgSlot(gc.str)
     };
-    ASSEMBLYREF ResultingAssemblyRef = (ASSEMBLYREF) onResourceResolve.Call_RetOBJECTREF(args);
-    if (ResultingAssemblyRef != NULL)
+    gc.AssemblyRef = (ASSEMBLYREF) onResourceResolve.Call_RetOBJECTREF(args);
+    if (gc.AssemblyRef != NULL)
     {
-        pResolvedAssembly = ResultingAssemblyRef->GetAssembly();
+        _ASSERTE(CoreLibBinder::IsClass(gc.AssemblyRef->GetMethodTable(), CLASS__ASSEMBLY));
+
+        pResolvedAssembly = gc.AssemblyRef->GetAssembly();
         if (pResolvedAssembly->IsCollectible())
         {
             COMPlusThrow(kNotSupportedException, W("NotSupported_CollectibleAssemblyResolve"));
@@ -4085,7 +4089,7 @@ AppDomain::RaiseAssemblyResolveEvent(
     Assembly* pAssembly = NULL;
 
     struct {
-        OBJECTREF AssemblyRef;
+        ASSEMBLYREF AssemblyRef;
         STRINGREF str;
     } gc;
     gc.AssemblyRef = NULL;
@@ -4095,7 +4099,7 @@ AppDomain::RaiseAssemblyResolveEvent(
     {
         if (pSpec->GetParentAssembly() != NULL)
         {
-            gc.AssemblyRef=pSpec->GetParentAssembly()->GetExposedObject();
+            gc.AssemblyRef=(ASSEMBLYREF)pSpec->GetParentAssembly()->GetExposedObject();
         }
 
         MethodDescCallSite onAssemblyResolve(METHOD__ASSEMBLYLOADCONTEXT__ON_ASSEMBLY_RESOLVE);
@@ -4106,11 +4110,13 @@ AppDomain::RaiseAssemblyResolveEvent(
             ObjToArgSlot(gc.str)
         };
 
-        ASSEMBLYREF ResultingAssemblyRef = (ASSEMBLYREF) onAssemblyResolve.Call_RetOBJECTREF(args);
+        gc.AssemblyRef = (ASSEMBLYREF) onAssemblyResolve.Call_RetOBJECTREF(args);
 
-        if (ResultingAssemblyRef != NULL)
+        if (gc.AssemblyRef != NULL)
         {
-            pAssembly = ResultingAssemblyRef->GetAssembly();
+            _ASSERTE(CoreLibBinder::IsClass(gc.AssemblyRef->GetMethodTable(), CLASS__ASSEMBLY));
+
+            pAssembly = gc.AssemblyRef->GetAssembly();
             if (pAssembly->IsCollectible())
             {
                 COMPlusThrow(kNotSupportedException, W("NotSupported_CollectibleAssemblyResolve"));
@@ -4543,6 +4549,8 @@ HRESULT RuntimeInvokeHostAssemblyResolver(INT_PTR pManagedAssemblyLoadContextToB
             // If we are here, assembly was successfully resolved via Load or Resolving events.
             _ASSERTE(_gcRefs.oRefLoadedAssembly != NULL);
 
+            _ASSERTE(CoreLibBinder::IsClass(_gcRefs.oRefLoadedAssembly->GetMethodTable(), CLASS__ASSEMBLY));
+
             // We were able to get the assembly loaded. Now, get its name since the host could have
             // performed the resolution using an assembly with different name.
             DomainAssembly *pDomainAssembly = _gcRefs.oRefLoadedAssembly->GetDomainAssembly();