diff --git a/src/vppinfra/linux/mem.c b/src/vppinfra/linux/mem.c
index d86402a..5826a6a 100644
--- a/src/vppinfra/linux/mem.c
+++ b/src/vppinfra/linux/mem.c
@@ -347,7 +347,7 @@
 uword
 clib_mem_vm_reserve (uword start, uword size, u32 log2_page_sz)
 {
-  uword off, pagesize = 1 << log2_page_sz;
+  uword off, pagesize = 1ULL << log2_page_sz;
   int mmap_flags = MAP_PRIVATE | MAP_ANONYMOUS;
   u8 *p;