--- a/browser/app/profile/firefox.js
+++ b/browser/app/profile/firefox.js
@@ -1556,17 +1556,17 @@ pref("extensions.interposition.enabled",
 pref("extensions.interposition.prefetching", true);
 
 // But don't allow non-MPC extensions by default on Nightly
 #if defined(NIGHTLY_BUILD)
 pref("extensions.allow-non-mpc-extensions", false);
 #endif
 
 // Enable blocking of e10s and e10s-multi for add-on users on beta/release.
-#ifdef RELEASE_OR_BETA
+#if defined(RELEASE_OR_BETA) && !defined(MOZ_DEV_EDITION)
 pref("extensions.e10sBlocksEnabling", true);
 pref("extensions.e10sMultiBlocksEnabling", true);
 #endif
 
 // How often to check for CPOW timeouts. CPOWs are only timed out by
 // the hang monitor.
 pref("dom.ipc.cpow.timeout", 500);