diff --git a/toolkit/mozapps/extensions/test/browser/browser_globalwarnings.js b/toolkit/mozapps/extensions/test/browser/browser_globalwarnings.js
index 787303c8f7e7..0541f0c9afef 100644
--- a/toolkit/mozapps/extensions/test/browser/browser_globalwarnings.js
+++ b/toolkit/mozapps/extensions/test/browser/browser_globalwarnings.js
@@ -16,8 +16,23 @@ function end_test() {
 add_test(function() {
   info("Testing compatibility checking warning");
 
-  info("Setting checkCompatibility to false");
-  AddonManager.checkCompatibility = false;
+  var channel = "default";
+  try {
+    channel = Services.prefs.getCharPref("app.update.channel");
+  }
+  catch (e) { }
+  if (channel != "aurora" &&
+      channel != "beta" &&
+      channel != "release") {
+    var version = "nightly";
+  }
+  else {
+    version = Services.appinfo.version.replace(/^([^\.]+\.[0-9]+[a-z]*).*/gi, "$1");
+  }
+
+  var pref = "extensions.checkCompatibility." + version;
+  info("Setting " + pref + " pref to false")
+  Services.prefs.setBoolPref(pref, false);
 
   open_manager("addons://list/extension", function(aWindow) {
     var hbox = aWindow.document.querySelector("#list-view hbox.global-warning-checkcompatibility");
diff --git a/toolkit/mozapps/extensions/test/browser/browser_searching.js b/toolkit/mozapps/extensions/test/browser/browser_searching.js
index 8eac0d92742a..4d5218c7c994 100644
--- a/toolkit/mozapps/extensions/test/browser/browser_searching.js
+++ b/toolkit/mozapps/extensions/test/browser/browser_searching.js
@@ -19,6 +19,22 @@ var gProvider;
 var gServer;
 var gAddonInstalled = false;
 
+var channel = "default";
+try {
+  channel = Services.prefs.getCharPref("app.update.channel");
+}
+catch (e) { }
+if (channel != "aurora" &&
+    channel != "beta" &&
+    channel != "release") {
+  var version = "nightly";
+}
+else {
+  version = Services.appinfo.version.replace(/^([^\.]+\.[0-9]+[a-z]*).*/gi, "$1");
+}
+
+const COMPATIBILITY_PREF = "extensions.checkCompatibility." + version;
+
 function test() {
   requestLongerTimeout(2);
   // Turn on searching for this test
@@ -592,7 +608,7 @@ add_test(function() {
 
 // Tests that incompatible add-ons are shown with a warning if compatibility checking is disabled
 add_test(function() {
-  AddonManager.checkCompatiblity = false;
+  Services.prefs.setBoolPref(COMPATIBILITY_PREF, false);
   search("incompatible", false, function() {
     var item = get_addon_item("remote5");
     is_element_visible(item, "Incompatible addon should be visible");
@@ -601,7 +617,7 @@ add_test(function() {
     var item = get_addon_item("remote6");
     is(item, null, "Addon incompatible with the product should not be visible");
 
-    AddonManager.checkCompatiblity = true;
+    Services.prefs.clearUserPref(COMPATIBILITY_PREF);
     run_next_test();
   });
 });
diff --git a/toolkit/mozapps/extensions/test/xpcshell/head_addons.js b/toolkit/mozapps/extensions/test/xpcshell/head_addons.js
index cad208a1bd39..d988358dad8f 100644
--- a/toolkit/mozapps/extensions/test/xpcshell/head_addons.js
+++ b/toolkit/mozapps/extensions/test/xpcshell/head_addons.js
@@ -26,10 +26,6 @@ var gAddonsList;
 
 var TEST_UNPACKED = false;
 
-function isNightlyChannel(channel) {
-  return channel != "aurora" && channel != "beta" && channel != "release" && channel != "esr";
-}
-
 function createAppInfo(id, name, version, platformVersion) {
   gAppInfo = {
     // nsIXULAppInfo
diff --git a/toolkit/mozapps/extensions/test/xpcshell/test_AddonRepository_compatmode.js b/toolkit/mozapps/extensions/test/xpcshell/test_AddonRepository_compatmode.js
index 7a922e1218d4..83f896800bc9 100644
--- a/toolkit/mozapps/extensions/test/xpcshell/test_AddonRepository_compatmode.js
+++ b/toolkit/mozapps/extensions/test/xpcshell/test_AddonRepository_compatmode.js
@@ -15,6 +15,19 @@ function run_test() {
   do_test_pending();
   createAppInfo("xpcshell@tests.mozilla.org", "XPCShell", "1", "1.9.2");
 
+  var channel = "default";
+  try {
+    channel = Services.prefs.getCharPref("app.update.channel");
+  } catch (e) { }
+  if (channel != "aurora" &&
+      channel != "beta" &&
+      channel != "release") {
+    var version = "nightly";
+  } else {
+    version = Services.appinfo.version.replace(/^([^\.]+\.[0-9]+[a-z]*).*/gi, "$1");
+  }
+  COMPATIBILITY_PREF = "extensions.checkCompatibility." + version;
+
   // Create and configure the HTTP server.
   gServer = new nsHttpServer();
   gServer.registerDirectory("/data/", do_get_file("data"));
@@ -71,7 +84,7 @@ function run_test_2() {
 // Compatibility checking disabled.
 function run_test_3() {
   do_print("Testing with all compatibility checking disabled");
-  AddonManager.checkCompatibility = false;
+  Services.prefs.setBoolPref(COMPATIBILITY_PREF, false);
 
   AddonRepository.searchAddons("test", 6, {
     searchSucceeded: function(aAddons) {
diff --git a/toolkit/mozapps/extensions/test/xpcshell/test_bug470377_2.js b/toolkit/mozapps/extensions/test/xpcshell/test_bug470377_2.js
index c23e024fa0c4..2cecdfe29b92 100644
--- a/toolkit/mozapps/extensions/test/xpcshell/test_bug470377_2.js
+++ b/toolkit/mozapps/extensions/test/xpcshell/test_bug470377_2.js
@@ -38,8 +38,21 @@
 
 // Disables security checking our updates which haven't been signed
 Services.prefs.setBoolPref("extensions.checkUpdateSecurity", false);
+// Disables compatibility checking
+var channel = "default";
+try {
+  channel = Services.prefs.getCharPref("app.update.channel");
+}
+catch (e) { }
 
-AddonManager.checkCompatibility = false;
+if (channel != "aurora" &&
+    channel != "beta" &&
+    channel != "release") {
+  Services.prefs.setBoolPref("extensions.checkCompatibility.nightly", false);
+}
+else {
+  Services.prefs.setBoolPref("extensions.checkCompatibility.2", false);
+}
 
 var ADDONS = [
   "test_bug470377_1",
diff --git a/toolkit/mozapps/extensions/test/xpcshell/test_bug470377_3.js b/toolkit/mozapps/extensions/test/xpcshell/test_bug470377_3.js
index 36b50cffc584..3e019db1be8c 100644
--- a/toolkit/mozapps/extensions/test/xpcshell/test_bug470377_3.js
+++ b/toolkit/mozapps/extensions/test/xpcshell/test_bug470377_3.js
@@ -102,8 +102,21 @@ function run_test_1() {
 }
 
 function run_test_2() {
-  AddonManager.checkCompatibility = false;
+  // Disable compatibility checks
+  var channel = "default";
+  try {
+    channel = Services.prefs.getCharPref("app.update.channel");
+  }
+  catch (e) { }
 
+  if (channel != "aurora" &&
+      channel != "beta" &&
+      channel != "release") {
+    Services.prefs.setBoolPref("extensions.checkCompatibility.nightly", false);
+  }
+  else {
+    Services.prefs.setBoolPref("extensions.checkCompatibility.2.2", false);
+  }
   restartManager();
 
   AddonManager.getAddonsByIDs(["bug470377_1@tests.mozilla.org",
diff --git a/toolkit/mozapps/extensions/test/xpcshell/test_bug470377_3_strictcompat.js b/toolkit/mozapps/extensions/test/xpcshell/test_bug470377_3_strictcompat.js
index dc0b44226349..f0e8f426606a 100644
--- a/toolkit/mozapps/extensions/test/xpcshell/test_bug470377_3_strictcompat.js
+++ b/toolkit/mozapps/extensions/test/xpcshell/test_bug470377_3_strictcompat.js
@@ -101,8 +101,21 @@ function run_test_1() {
 }
 
 function run_test_2() {
-  AddonManager.checkCompatibility = false;
+  // Disable compatibility checks
+  var channel = "default";
+  try {
+    channel = Services.prefs.getCharPref("app.update.channel");
+  }
+  catch (e) { }
 
+  if (channel != "aurora" &&
+      channel != "beta" &&
+      channel != "release") {
+    Services.prefs.setBoolPref("extensions.checkCompatibility.nightly", false);
+  }
+  else {
+    Services.prefs.setBoolPref("extensions.checkCompatibility.2.2", false);
+  }
   restartManager();
 
   AddonManager.getAddonsByIDs(["bug470377_1@tests.mozilla.org",
diff --git a/toolkit/mozapps/extensions/test/xpcshell/test_bug470377_4.js b/toolkit/mozapps/extensions/test/xpcshell/test_bug470377_4.js
index d66d729738cb..3958ad681da5 100644
--- a/toolkit/mozapps/extensions/test/xpcshell/test_bug470377_4.js
+++ b/toolkit/mozapps/extensions/test/xpcshell/test_bug470377_4.js
@@ -36,6 +36,21 @@
  * ***** END LICENSE BLOCK *****
  */
 
+var channel = "default";
+try {
+  channel = Services.prefs.getCharPref("app.update.channel");
+}
+catch (e) { }
+
+if (channel != "aurora" &&
+    channel != "beta" &&
+    channel != "release") {
+  var checkCompatPref = "extensions.checkCompatibility.nightly";
+}
+else {
+  checkCompatPref = "extensions.checkCompatibility.2.1a";
+}
+
 function run_test() {
   do_test_pending();
   createAppInfo("xpcshell@tests.mozilla.org", "XPCShell", "2.1a4", "2");
@@ -73,8 +88,8 @@ function run_test() {
 }
 
 function run_test_1() {
-  AddonManager.checkCompatibility = false;
-
+  // Disable compatibility checks
+  Services.prefs.setBoolPref(checkCompatPref, false);
   startupManager();
 
   AddonManager.getAddonsByIDs(["bug470377_1@tests.mozilla.org",
@@ -99,8 +114,8 @@ function run_test_1() {
 }
 
 function run_test_2() {
-  AddonManager.checkCompatibility = true;
-
+  // Enable compatibility checks
+  Services.prefs.setBoolPref(checkCompatPref, true);
   restartManager();
 
   AddonManager.getAddonsByIDs(["bug470377_1@tests.mozilla.org",
diff --git a/toolkit/mozapps/extensions/test/xpcshell/test_bug521905.js b/toolkit/mozapps/extensions/test/xpcshell/test_bug521905.js
index daa5b89a8670..1bbb1b403699 100644
--- a/toolkit/mozapps/extensions/test/xpcshell/test_bug521905.js
+++ b/toolkit/mozapps/extensions/test/xpcshell/test_bug521905.js
@@ -41,7 +41,8 @@ const ID = "bug521905@tests.mozilla.org";
 
 // Disables security checking our updates which haven't been signed
 Services.prefs.setBoolPref("extensions.checkUpdateSecurity", false);
-AddonManager.checkCompatibility = false;
+// Disables compatibility checking
+Services.prefs.setBoolPref("extensions.checkCompatibility.2.0pre", false);
 
 function run_test() {
   var channel = "default";
@@ -52,7 +53,9 @@ function run_test() {
 
   // This test is only relevant on builds where the version is included in the
   // checkCompatibility preference name
-  if (isNightlyChannel(channel)) {
+  if (channel != "aurora" &&
+      channel != "beta" &&
+      channel != "release") {
     return;
   }
 
diff --git a/toolkit/mozapps/extensions/test/xpcshell/test_checkcompatibility.js b/toolkit/mozapps/extensions/test/xpcshell/test_checkcompatibility.js
index f30c45387212..a49cafc7bd26 100644
--- a/toolkit/mozapps/extensions/test/xpcshell/test_checkcompatibility.js
+++ b/toolkit/mozapps/extensions/test/xpcshell/test_checkcompatibility.js
@@ -59,6 +59,8 @@ var ADDONS = [{
 const profileDir = gProfD.clone();
 profileDir.append("extensions");
 
+var gIsNightly = false;
+
 function run_test() {
   do_test_pending();
   createAppInfo("xpcshell@tests.mozilla.org", "XPCShell", "2.2.3", "2");
@@ -67,6 +69,16 @@ function run_test() {
     writeInstallRDFForExtension(a, profileDir);
   });
 
+  var channel = "default";
+  try {
+    channel = Services.prefs.getCharPref("app.update.channel");
+  }
+  catch (e) { }
+
+  gIsNightly = channel != "aurora" &&
+               channel != "beta" &&
+               channel != "release";
+
   startupManager();
 
   run_test_1();
@@ -133,8 +145,10 @@ function run_test_1() {
 // Tests that with compatibility checking disabled we see the incompatible
 // add-ons enabled
 function run_test_2() {
-  AddonManager.checkCompatibility = false;
-
+  if (gIsNightly)
+    Services.prefs.setBoolPref("extensions.checkCompatibility.nightly", false);
+  else
+    Services.prefs.setBoolPref("extensions.checkCompatibility.2.2", false);
   restartManager();
 
   AddonManager.getAddonsByIDs(["addon1@tests.mozilla.org",
@@ -152,14 +166,8 @@ function run_test_2() {
 // Tests that with compatibility checking disabled we see the incompatible
 // add-ons enabled.
 function run_test_3() {
-  var channel = "default";
-  try {
-    channel = Services.prefs.getCharPref("app.update.channel");
-  }
-  catch (e) { }
-
-  if (!isNightlyChannel(channel))
-    AddonManager.checkCompatibility = false;
+  if (!gIsNightly)
+    Services.prefs.setBoolPref("extensions.checkCompatibility.2.1a", false);
   restartManager("2.1a4");
 
   AddonManager.getAddonsByIDs(["addon1@tests.mozilla.org",
@@ -177,8 +185,10 @@ function run_test_3() {
 // Tests that with compatibility checking enabled we see the incompatible
 // add-ons disabled.
 function run_test_4() {
-  AddonManager.checkCompatibility = true;
-
+  if (gIsNightly)
+    Services.prefs.setBoolPref("extensions.checkCompatibility.nightly", true);
+  else
+    Services.prefs.setBoolPref("extensions.checkCompatibility.2.1a", true);
   restartManager();
 
   AddonManager.getAddonsByIDs(["addon1@tests.mozilla.org",
diff --git a/toolkit/mozapps/extensions/test/xpcshell/test_pref_properties.js b/toolkit/mozapps/extensions/test/xpcshell/test_pref_properties.js
index 6ec1c376f864..7914029b7464 100644
--- a/toolkit/mozapps/extensions/test/xpcshell/test_pref_properties.js
+++ b/toolkit/mozapps/extensions/test/xpcshell/test_pref_properties.js
@@ -132,7 +132,9 @@ function run_test() {
   try {
     channel = Services.prefs.getCharPref("app.update.channel");
   } catch (e) { }
-  if (isNightlyChannel(channel)) {
+  if (channel != "aurora" &&
+      channel != "beta" &&
+      channel != "release") {
     var version = "nightly";
   } else {
     version = Services.appinfo.version.replace(/^([^\.]+\.[0-9]+[a-z]*).*/gi, "$1");
diff --git a/toolkit/mozapps/extensions/test/xpcshell/test_update_compatmode.js b/toolkit/mozapps/extensions/test/xpcshell/test_update_compatmode.js
index 20ddc715ddc2..b4024e192646 100644
--- a/toolkit/mozapps/extensions/test/xpcshell/test_update_compatmode.js
+++ b/toolkit/mozapps/extensions/test/xpcshell/test_update_compatmode.js
@@ -14,10 +14,25 @@ var testserver;
 const profileDir = gProfD.clone();
 profileDir.append("extensions");
 
+var COMPATIBILITY_PREF;
+
 function run_test() {
   do_test_pending();
   createAppInfo("xpcshell@tests.mozilla.org", "XPCShell", "1", "1.9.2");
   
+  var channel = "default";
+  try {
+    channel = Services.prefs.getCharPref("app.update.channel");
+  } catch (e) { }
+  if (channel != "aurora" &&
+      channel != "beta" &&
+      channel != "release") {
+    var version = "nightly";
+  } else {
+    version = Services.appinfo.version.replace(/^([^\.]+\.[0-9]+[a-z]*).*/gi, "$1");
+  }  
+  COMPATIBILITY_PREF = "extensions.checkCompatibility." + version;
+
   // Create and configure the HTTP server.
   testserver = new nsHttpServer();
   testserver.registerDirectory("/data/", do_get_file("data"));
@@ -159,7 +174,7 @@ function run_test_3() {
 // Compatibility checking disabled.
 function run_test_4() {
   do_print("Testing with all compatibility checking disabled");
-  AddonManager.checkCompatibility = false;
+  Services.prefs.setBoolPref(COMPATIBILITY_PREF, false);
   AddonManager.getAddonByID("compatmode-ignore@tests.mozilla.org", function(addon) {
     do_check_neq(addon, null);
     addon.findUpdates({
diff --git a/toolkit/mozapps/extensions/test/xpcshell/test_updatecheck.js b/toolkit/mozapps/extensions/test/xpcshell/test_updatecheck.js
index 8581bcd530d2..f3b9b34b1ab9 100644
--- a/toolkit/mozapps/extensions/test/xpcshell/test_updatecheck.js
+++ b/toolkit/mozapps/extensions/test/xpcshell/test_updatecheck.js
@@ -6,12 +6,24 @@
 
 Components.utils.import("resource://gre/modules/AddonUpdateChecker.jsm");
 
+var COMPATIBILITY_PREF;
+
 do_load_httpd_js();
 var testserver;
 
 function run_test() {
   createAppInfo("xpcshell@tests.mozilla.org", "XPCShell", "1", "1.9.2");
 
+  var channel = "default";
+  try {
+    channel = Services.prefs.getCharPref("app.update.channel");
+  } catch (e) { }
+  if (channel != "aurora" && channel != "beta" && channel != "release")
+    var version = "nightly";
+  else
+    version = Services.appinfo.version.replace(/^([^\.]+\.[0-9]+[a-z]*).*/gi, "$1");
+  COMPATIBILITY_PREF = "extensions.checkCompatibility." + version;
+
   // Create and configure the HTTP server.
   testserver = new nsHttpServer();
   testserver.registerDirectory("/data/", do_get_file("data"));