diff --git a/src/vlib/linux/pci.c b/src/vlib/linux/pci.c
index e049b23..9f0629f 100644
--- a/src/vlib/linux/pci.c
+++ b/src/vlib/linux/pci.c
@@ -390,7 +390,7 @@
   u8 *rel_path = 0, *abs_path = 0, *link_path = 0;
   unformat_input_t input;
   int fd = open (sysfs_pci_dev_path, O_RDONLY);
-  u32 size = 0;
+  ssize_t size = 0;
   u32 domain = 0, bus;
   clib_error_t *err = NULL;