diff --git a/include/jemalloc/internal/jemalloc_internal.h.in b/include/jemalloc/internal/jemalloc_internal.h.in
index 6270a08e..381bd609 100644
--- a/include/jemalloc/internal/jemalloc_internal.h.in
+++ b/include/jemalloc/internal/jemalloc_internal.h.in
@@ -287,7 +287,7 @@ static const bool config_ivsalloc =
 #  ifdef __powerpc__
 #    define LG_QUANTUM		4
 #  endif
-#  ifdef __s390x__
+#  ifdef __s390__
 #    define LG_QUANTUM		4
 #  endif
 #  ifdef __SH4__