diff --git a/post/lib_ppc/string.c b/post/lib_ppc/string.c
index b2daa88..3683ac9 100644
--- a/post/lib_ppc/string.c
+++ b/post/lib_ppc/string.c
@@ -47,6 +47,7 @@
 {
     int ret = 0;
     unsigned int i;
+    int flag = disable_interrupts();
 
     if (ret == 0)
     {
@@ -97,6 +98,9 @@
 	post_log ("Error at string test !\n");
     }
 
+    if (flag)
+	enable_interrupts();
+
     return ret;
 }