--- a/modules/libpref/init/all.js
+++ b/modules/libpref/init/all.js
@@ -1269,12 +1269,7 @@ pref("javascript.options.mem.gc_max_empty_chunk_count", 30);
 
 pref("javascript.options.showInConsole", false);
 
-#ifdef RELEASE_OR_BETA
-// Disabled in Beta and Release for now, see bug 1225406
 pref("javascript.options.shared_memory", false);
-#else
-pref("javascript.options.shared_memory", true);
-#endif
 
 pref("javascript.options.throw_on_debuggee_would_run", false);
 pref("javascript.options.dump_stack_on_debuggee_would_run", false);