diff --git a/browser/app/profile/firefox.js b/browser/app/profile/firefox.js
index 1560e0fd9db4..4f3d5b020aea 100644
--- a/browser/app/profile/firefox.js
+++ b/browser/app/profile/firefox.js
@@ -1799,11 +1799,5 @@ pref("extensions.interposition.prefetching", true);
pref("browser.defaultbrowser.notificationbar", false);
-// How often to check for CPOW timeouts. CPOWs are only timed out by
-// the hang monitor.
-pref("dom.ipc.cpow.timeout", 500);
-
-// Enable e10s hang monitoring (slow script checking and plugin hang
-// detection).
-pref("dom.ipc.processHangMonitor", true);
-pref("dom.ipc.reportProcessHangs", true);
+// How many milliseconds to wait for a CPOW response from the child process.
+pref("dom.ipc.cpow.timeout", 0);
diff --git a/browser/base/content/browser.js b/browser/base/content/browser.js
index 1c3d10b95758..1272d131ded4 100644
--- a/browser/base/content/browser.js
+++ b/browser/base/content/browser.js
@@ -149,9 +149,6 @@ XPCOMUtils.defineLazyModuleGetter(this, "Social",
XPCOMUtils.defineLazyModuleGetter(this, "PageThumbs",
"resource://gre/modules/PageThumbs.jsm");
-XPCOMUtils.defineLazyModuleGetter(this, "ProcessHangMonitor",
- "resource:///modules/ProcessHangMonitor.jsm");
-
#ifdef MOZ_SAFE_BROWSING
XPCOMUtils.defineLazyModuleGetter(this, "SafeBrowsing",
"resource://gre/modules/SafeBrowsing.jsm");
diff --git a/browser/base/content/browser.xul b/browser/base/content/browser.xul
index 8afeecd913ba..a42f415bf87b 100644
--- a/browser/base/content/browser.xul
+++ b/browser/base/content/browser.xul
@@ -334,26 +334,6 @@
orient="horizontal"
hidden="true"/>
-
-
-
-
-
-
-