--- a/include/jemalloc/internal/jemalloc_internal_defs-linux.h	(index)
+++ b/include/jemalloc/internal/jemalloc_internal_defs-linux.h	(working tree)
@@ -289,1 +289,1 @@
-/* #undef JEMALLOC_DEFINE_MADVISE_FREE */
+#define JEMALLOC_DEFINE_MADVISE_FREE