diff --git a/tests/slice-threadinit.c b/tests/slice-threadinit.c
index f29dcbed1..30b186147 100644
--- a/tests/slice-threadinit.c
+++ b/tests/slice-threadinit.c
@@ -70,7 +70,7 @@ int
 main (int   argc,
       char *argv[])
 {
-  int j, n_pages = 0;
+  gsize j, n_pages = 0;
   void *mps[N_MAGAZINE_PROBES];
 
   /* probe some magazine sizes */