diff --git a/testsuite/testutils.c b/testsuite/testutils.c
index 8f296b0808151139e8aa59b4656db61f2136a804..cfcc07341b6fc74ffba5289cbfce087748e5b3b8 100644
--- a/testsuite/testutils.c
+++ b/testsuite/testutils.c
@@ -14,7 +14,7 @@
 #include <unistd.h>
 
 /* -1 means invalid */
-const signed char hex_digits[0x100] =
+static const signed char hex_digits[0x100] =
   {
     -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,
     -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,