--- a/browser/app/profile/firefox.js
+++ b/browser/app/profile/firefox.js
@@ -1622,17 +1622,23 @@ pref("toolkit.pageThumbs.minHeight", 190
 
 // Enable speech synthesis
 pref("media.webspeech.synth.enabled", true);
 
 pref("browser.esedbreader.loglevel", "Error");
 
 pref("browser.laterrun.enabled", false);
 
+// Disable prelaunch in the same way activity-stream is enabled addressing
+// bug 1381804 memory usage until bug 1376895 is fixed.
+#ifdef NIGHTLY_BUILD
+pref("dom.ipc.processPrelaunch.enabled", false);
+#else
 pref("dom.ipc.processPrelaunch.enabled", true);
+#endif
 
 #ifdef EARLY_BETA_OR_EARLIER
 pref("browser.migrate.automigrate.enabled", true);
 #else
 pref("browser.migrate.automigrate.enabled", false);
 #endif
 // 4 here means the suggestion notification will be automatically
 // hidden the 4th day, so it will actually be shown on 3 different days.