--- a/memory/mozjemalloc/jemalloc.c
+++ b/memory/mozjemalloc/jemalloc.c
@@ -5066,22 +5066,16 @@ MALLOC_OUT:
 
 	malloc_initialized = true;
 
 #if !defined(MOZ_MEMORY_WINDOWS) && !defined(MOZ_MEMORY_DARWIN)
 	/* Prevent potential deadlock on malloc locks after fork. */
 	pthread_atfork(_malloc_prefork, _malloc_postfork_parent, _malloc_postfork_child);
 #endif
 
-#if defined(NEEDS_PTHREAD_MMAP_UNALIGNED_TSD)
-	if (pthread_key_create(&mmap_unaligned_tsd, NULL) != 0) {
-		malloc_printf("<jemalloc>: Error in pthread_key_create()\n");
-	}
-#endif
-
 #if defined(MOZ_MEMORY_DARWIN)
 	register_zone();
 #endif
 
 #ifndef MOZ_MEMORY_WINDOWS
 	malloc_mutex_unlock(&init_lock);
 #endif
 	return (false);