diff --git a/src/vlib/linux/physmem.c b/src/vlib/linux/physmem.c
index 4d16486..dbc4c54 100755
--- a/src/vlib/linux/physmem.c
+++ b/src/vlib/linux/physmem.c
@@ -179,7 +179,7 @@
   pr->log2_page_size = alloc.log2_page_size;
   pr->n_pages = alloc.n_pages;
   pr->size = (u64) pr->n_pages << (u64) pr->log2_page_size;
-  pr->page_mask = (1 << pr->log2_page_size) - 1;
+  pr->page_mask = (1ull << pr->log2_page_size) - 1;
   pr->numa_node = numa_node;
   pr->name = format (0, "%s%c", name, 0);