diff --git a/dlls/oleaut32/tmarshal.c b/dlls/oleaut32/tmarshal.c
index cf82a31ea6c..0d4f85adc05 100644
--- a/dlls/oleaut32/tmarshal.c
+++ b/dlls/oleaut32/tmarshal.c
@@ -608,9 +608,35 @@ serialize_param(
     }
     case VT_PTR: {
 	DWORD cookie;
-	BOOL        derefhere;
+	BOOL        derefhere = TRUE;
 
-	derefhere = (tdesc->u.lptdesc->vt != VT_USERDEFINED);
+	if (tdesc->u.lptdesc->vt == VT_USERDEFINED) {
+	    ITypeInfo	*tinfo2;
+	    TYPEATTR	*tattr;
+
+	    hres = ITypeInfo_GetRefTypeInfo(tinfo,tdesc->u.lptdesc->u.hreftype,&tinfo2);
+	    if (hres) {
+		ERR("Could not get typeinfo of hreftype %lx for VT_USERDEFINED.\n",tdesc->u.lptdesc->u.hreftype);
+		return hres;
+	    }
+	    ITypeInfo_GetTypeAttr(tinfo2,&tattr);
+	    switch (tattr->typekind) {
+	    case TKIND_ENUM:	/* confirmed */
+	    case TKIND_RECORD:	/* FIXME: mostly untested */
+		derefhere=TRUE;
+		break;
+	    case TKIND_ALIAS:	/* FIXME: untested */
+	    case TKIND_DISPATCH:	/* will be done in VT_USERDEFINED case */
+	    case TKIND_INTERFACE:	/* will be done in VT_USERDEFINED case */
+		derefhere=FALSE;
+		break;
+	    default:
+		FIXME("unhandled switch cases tattr->typekind %d\n", tattr->typekind);
+		derefhere=FALSE;
+		break;
+	    }
+	    ITypeInfo_Release(tinfo2);
+	}
 
 	if (debugout) TRACE_(olerelay)("*");
 	/* Write always, so the other side knows when it gets a NULL pointer.
@@ -1184,9 +1210,35 @@ deserialize_param(
 	}
 	case VT_PTR: {
 	    DWORD	cookie;
-	    BOOL        derefhere = 0;
+	    BOOL        derefhere = TRUE;
 
-	    derefhere = (tdesc->u.lptdesc->vt != VT_USERDEFINED);
+	    if (tdesc->u.lptdesc->vt == VT_USERDEFINED) {
+		ITypeInfo	*tinfo2;
+		TYPEATTR	*tattr;
+
+		hres = ITypeInfo_GetRefTypeInfo(tinfo,tdesc->u.lptdesc->u.hreftype,&tinfo2);
+		if (hres) {
+		    ERR("Could not get typeinfo of hreftype %lx for VT_USERDEFINED.\n",tdesc->u.lptdesc->u.hreftype);
+		    return hres;
+		}
+		ITypeInfo_GetTypeAttr(tinfo2,&tattr);
+		switch (tattr->typekind) {
+		case TKIND_ENUM:	/* confirmed */
+		case TKIND_RECORD:	/* FIXME: mostly untested */
+		    derefhere=TRUE;
+		    break;
+		case TKIND_ALIAS:	/* FIXME: untested */
+		case TKIND_DISPATCH:	/* will be done in VT_USERDEFINED case */
+		case TKIND_INTERFACE:	/* will be done in VT_USERDEFINED case */
+		    derefhere=FALSE;
+		    break;
+		default:
+		    FIXME("unhandled switch cases tattr->typekind %d\n", tattr->typekind);
+		    derefhere=FALSE;
+		    break;
+		}
+		ITypeInfo_Release(tinfo2);
+	    }
 	    /* read it in all cases, we need to know if we have 
 	     * NULL pointer or not.
 	     */