diff --git a/include/asm-sparc64/a.out.h b/include/asm-sparc64/a.out.h
index 02af289..faac321 100644
--- a/include/asm-sparc64/a.out.h
+++ b/include/asm-sparc64/a.out.h
@@ -95,7 +95,9 @@
 
 #ifdef __KERNEL__
 
-#define STACK_TOP (test_thread_flag(TIF_32BIT) ? 0xf0000000 : 0x80000000000L)
+#define STACK_TOP (test_thread_flag(TIF_32BIT) ? \
+		   0xf0000000 : \
+		   (0x0000080000000000UL - (1UL << 32UL)))
 
 #endif