diff --git a/mobile/android/app/mobile.js b/mobile/android/app/mobile.js
index 4fdc33dad14..036411ba5fe 100644
--- a/mobile/android/app/mobile.js
+++ b/mobile/android/app/mobile.js
@@ -218,8 +218,10 @@ pref("extensions.logging.enabled", false);
 pref("extensions.hideInstallButton", true);
 pref("extensions.showMismatchUI", false);
 pref("extensions.hideUpdateButton", false);
+pref("extensions.strictCompatibility", false);
+pref("extensions.minCompatibleAppVersion", "11.0");
 
-pref("extensions.update.url", "https://versioncheck.addons.mozilla.org/update/VersionCheck.php?reqVersion=%REQ_VERSION%&id=%ITEM_ID%&version=%ITEM_VERSION%&maxAppVersion=%ITEM_MAXAPPVERSION%&status=%ITEM_STATUS%&appID=%APP_ID%&appVersion=%APP_VERSION%&appOS=%APP_OS%&appABI=%APP_ABI%&locale=%APP_LOCALE%&currentAppVersion=%CURRENT_APP_VERSION%&updateType=%UPDATE_TYPE%");
+pref("extensions.update.url", "https://versioncheck.addons.mozilla.org/update/VersionCheck.php?reqVersion=%REQ_VERSION%&id=%ITEM_ID%&version=%ITEM_VERSION%&maxAppVersion=%ITEM_MAXAPPVERSION%&status=%ITEM_STATUS%&appID=%APP_ID%&appVersion=%APP_VERSION%&appOS=%APP_OS%&appABI=%APP_ABI%&locale=%APP_LOCALE%&currentAppVersion=%CURRENT_APP_VERSION%&updateType=%UPDATE_TYPE%&compatMode=%COMPATIBILITY_MODE%");
 
 /* preferences for the Get Add-ons pane */
 pref("extensions.getAddons.cache.enabled", true);
@@ -227,7 +229,7 @@ pref("extensions.getAddons.maxResults", 15);
 pref("extensions.getAddons.recommended.browseURL", "https://addons.mozilla.org/%LOCALE%/mobile/recommended/");
 pref("extensions.getAddons.recommended.url", "https://services.addons.mozilla.org/%LOCALE%/mobile/api/%API_VERSION%/list/featured/all/%MAX_RESULTS%/%OS%/%VERSION%");
 pref("extensions.getAddons.search.browseURL", "https://addons.mozilla.org/%LOCALE%/mobile/search?q=%TERMS%");
-pref("extensions.getAddons.search.url", "https://services.addons.mozilla.org/%LOCALE%/mobile/api/%API_VERSION%/search/%TERMS%/all/%MAX_RESULTS%/%OS%/%VERSION%");
+pref("extensions.getAddons.search.url", "https://services.addons.mozilla.org/%LOCALE%/mobile/api/%API_VERSION%/search/%TERMS%/all/%MAX_RESULTS%/%OS%/%VERSION%/%COMPATIBILITY_MODE%");
 pref("extensions.getAddons.browseAddons", "https://addons.mozilla.org/%LOCALE%/mobile/");
 pref("extensions.getAddons.get.url", "https://services.addons.mozilla.org/%LOCALE%/mobile/api/%API_VERSION%/search/guid:%IDS%?src=mobile&appOS=%OS%&appVersion=%VERSION%&tMain=%TIME_MAIN%&tFirstPaint=%TIME_FIRST_PAINT%&tSessionRestored=%TIME_SESSION_RESTORED%");
 
diff --git a/mobile/xul/app/mobile.js b/mobile/xul/app/mobile.js
index 93e916f2047..d0fce54c2a2 100644
--- a/mobile/xul/app/mobile.js
+++ b/mobile/xul/app/mobile.js
@@ -212,8 +212,10 @@ pref("extensions.logging.enabled", false);
 pref("extensions.hideInstallButton", true);
 pref("extensions.showMismatchUI", false);
 pref("extensions.hideUpdateButton", false);
+pref("extensions.strictCompatibility", false);
+pref("extensions.minCompatibleAppVersion", "4.0");
 
-pref("extensions.update.url", "https://versioncheck.addons.mozilla.org/update/VersionCheck.php?reqVersion=%REQ_VERSION%&id=%ITEM_ID%&version=%ITEM_VERSION%&maxAppVersion=%ITEM_MAXAPPVERSION%&status=%ITEM_STATUS%&appID=%APP_ID%&appVersion=%APP_VERSION%&appOS=%APP_OS%&appABI=%APP_ABI%&locale=%APP_LOCALE%&currentAppVersion=%CURRENT_APP_VERSION%&updateType=%UPDATE_TYPE%");
+pref("extensions.update.url", "https://versioncheck.addons.mozilla.org/update/VersionCheck.php?reqVersion=%REQ_VERSION%&id=%ITEM_ID%&version=%ITEM_VERSION%&maxAppVersion=%ITEM_MAXAPPVERSION%&status=%ITEM_STATUS%&appID=%APP_ID%&appVersion=%APP_VERSION%&appOS=%APP_OS%&appABI=%APP_ABI%&locale=%APP_LOCALE%&currentAppVersion=%CURRENT_APP_VERSION%&updateType=%UPDATE_TYPE%&compatMode=%COMPATIBILITY_MODE%");
 
 /* preferences for the Get Add-ons pane */
 pref("extensions.getAddons.cache.enabled", true);
@@ -221,7 +223,7 @@ pref("extensions.getAddons.maxResults", 15);
 pref("extensions.getAddons.recommended.browseURL", "https://addons.mozilla.org/%LOCALE%/mobile/recommended/");
 pref("extensions.getAddons.recommended.url", "https://services.addons.mozilla.org/%LOCALE%/mobile/api/%API_VERSION%/list/featured/all/%MAX_RESULTS%/%OS%/%VERSION%");
 pref("extensions.getAddons.search.browseURL", "https://addons.mozilla.org/%LOCALE%/mobile/search?q=%TERMS%");
-pref("extensions.getAddons.search.url", "https://services.addons.mozilla.org/%LOCALE%/mobile/api/%API_VERSION%/search/%TERMS%/all/%MAX_RESULTS%/%OS%/%VERSION%");
+pref("extensions.getAddons.search.url", "https://services.addons.mozilla.org/%LOCALE%/mobile/api/%API_VERSION%/search/%TERMS%/all/%MAX_RESULTS%/%OS%/%VERSION%/%COMPATIBILITY_MODE%");
 pref("extensions.getAddons.browseAddons", "https://addons.mozilla.org/%LOCALE%/mobile/");
 pref("extensions.getAddons.get.url", "https://services.addons.mozilla.org/%LOCALE%/mobile/api/%API_VERSION%/search/guid:%IDS%?src=mobile&appOS=%OS%&appVersion=%VERSION%&tMain=%TIME_MAIN%&tFirstPaint=%TIME_FIRST_PAINT%&tSessionRestored=%TIME_SESSION_RESTORED%");