diff --git a/gcc/ada/libgnarl/s-tporft.adb b/gcc/ada/libgnarl/s-tporft.adb
index 9d99eac80c2c3025f54a9ab2c3a10a9253b7ee73..634eae63ea325a0d0af596ea3c0554dc469174a1 100644
--- a/gcc/ada/libgnarl/s-tporft.adb
+++ b/gcc/ada/libgnarl/s-tporft.adb
@@ -53,6 +53,7 @@ begin
 
    Local_ATCB.Common.LL.Thread := Thread;
    Local_ATCB.Common.Current_Priority := System.Priority'First;
+   Local_ATCB.Common.Global_Task_Lock_Nesting := 0;
    Specific.Set (Local_ATCB'Unchecked_Access);
 
    --  It is now safe to use an allocator