diff --git a/include/unwind.h b/include/unwind.h
--- a/include/unwind.h
+++ b/include/unwind.h
@@ -70,7 +70,7 @@
 					      struct _Unwind_Exception *);
 
 typedef _Unwind_Reason_Code (*_Unwind_Stop_Fn) (int, _Unwind_Action,
-						__int64_t,
+						__uint64_t,
 						struct _Unwind_Exception *,
 						struct _Unwind_Context *,
 						void *);
@@ -82,7 +82,7 @@
    IA-64, while being more general.  */
 struct _Unwind_Exception
   {
-    __int64_t exception_class;
+    __uint64_t exception_class;
     _Unwind_Exception_Cleanup_Fn exception_cleanup;
     unsigned long private_1;
     unsigned long private_2;
diff --git a/lib/libthr/thread/thr_exit.c b/lib/libthr/thread/thr_exit.c
--- a/lib/libthr/thread/thr_exit.c
+++ b/lib/libthr/thread/thr_exit.c
@@ -61,7 +61,7 @@
 static void thread_uw_init(void);
 static _Unwind_Reason_Code thread_unwind_stop(int version,
 	_Unwind_Action actions,
-	int64_t exc_class,
+	uint64_t exc_class,
 	struct _Unwind_Exception *exc_obj,
 	struct _Unwind_Context *context, void *stop_parameter);
 /* unwind library pointers */
@@ -133,7 +133,7 @@
 
 static _Unwind_Reason_Code
 thread_unwind_stop(int version __unused, _Unwind_Action actions,
-	int64_t exc_class __unused,
+	uint64_t exc_class __unused,
 	struct _Unwind_Exception *exc_obj __unused,
 	struct _Unwind_Context *context, void *stop_parameter __unused)
 {