diff -up firefox-48.0/memory/mozjemalloc/jemalloc.c.jemalloc-ppc firefox-48.0/memory/mozjemalloc/jemalloc.c
--- firefox-48.0/memory/mozjemalloc/jemalloc.c.jemalloc-ppc	2016-07-26 10:51:46.385434384 +0200
+++ firefox-48.0/memory/mozjemalloc/jemalloc.c	2016-07-26 10:53:49.061023106 +0200
@@ -1090,7 +1090,7 @@ static const bool config_recycle = false
  * controlling the malloc behavior are defined as compile-time constants
  * for best performance and cannot be altered at runtime.
  */
-#if !defined(__ia64__) && !defined(__sparc__) && !defined(__mips__) && !defined(__aarch64__)
+#if !defined(__ia64__) && !defined(__sparc__) && !defined(__mips__) && !defined(__aarch64__) && !(defined(__powerpc__))
 #define MALLOC_STATIC_SIZES 1
 #endif