diff --git a/kernel/proc/proc.h b/kernel/proc/proc.h
index 6545f4c..1b2461d 100644
--- a/kernel/proc/proc.h
+++ b/kernel/proc/proc.h
@@ -19,8 +19,8 @@
 #define PROC_VFSHANDLES_MAX   0x80
 #define PROC_PIPEHANDLES_MAX  0x20
 
-#define PROC_MMAN_MAP_BASE  0x500000000000
-#define PROC_USER_STACK_TOP 0x800000000000
+#define PROC_MMAN_MAP_BASE  0x0000100000000000ULL
+#define PROC_USER_STACK_TOP 0x0000800000000000ULL
 
 typedef struct {
   IntrStackFrame trapframe;