--- a/memory/mozjemalloc/jemalloc.c
+++ b/memory/mozjemalloc/jemalloc.c
@@ -120,17 +120,17 @@
  * We therefore define MALLOC_DOUBLE_PURGE on Mac.  This causes jemalloc to
  * track which pages have been MADV_FREE'd.  You can then call
  * jemalloc_purge_freed_pages(), which will force the OS to release those
  * MADV_FREE'd pages, making the process's RSS reflect its true memory usage.
  *
  * The jemalloc_purge_freed_pages definition in memory/build/mozmemory.h needs
  * to be adjusted if MALLOC_DOUBLE_PURGE is ever enabled on Linux.
  */
-#ifdef MOZ_MEMORY_DARWIN
+#if defined(MOZ_MEMORY_DARWIN) || defined(MOZ_MEMORY_BSD)
 #define MALLOC_DOUBLE_PURGE
 #endif
 
 /*
  * MALLOC_PRODUCTION disables assertions and statistics gathering.  It also
  * defaults the A and J runtime options to off.  These settings are appropriate
  * for production systems.
  */