--- a/memory/build/zone.c
+++ b/memory/build/zone.c
@@ -231,17 +231,17 @@ zone_print(malloc_zone_t *zone, boolean_
 {
 }
 
 static void
 zone_log(malloc_zone_t *zone, void *address)
 {
 }
 
-#ifdef MOZ_JEMALLOC
+#ifdef MOZ_JEMALLOC4
 
 #include "jemalloc/internal/jemalloc_internal.h"
 
 static void
 zone_force_lock(malloc_zone_t *zone)
 {
   /* /!\ This calls into jemalloc. It works because we're linked in the
    * same library. Stolen from jemalloc's zone.c. */