diff --git a/firefox-redhat-default-prefs.js b/firefox-redhat-default-prefs.js
index d027bd8..dc31ddb 100644
--- a/firefox-redhat-default-prefs.js
+++ b/firefox-redhat-default-prefs.js
@@ -26,3 +26,4 @@ pref("media.gmp-gmpopenh264.enabled",false);
 pref("plugins.notifyMissingFlash", false);
 /* See https://bugzilla.redhat.com/show_bug.cgi?id=1226489 */
 pref("browser.display.use_system_colors", false);
+pref("layers.offmainthreadcomposition.enabled", false);
diff --git a/firefox.spec b/firefox.spec
index 16a2324..2ea05d3 100644
--- a/firefox.spec
+++ b/firefox.spec
@@ -807,6 +807,9 @@ gtk-update-icon-cache %{_datadir}/icons/hicolor &>/dev/null || :
 #---------------------------------------------------------------------
 
 %changelog
+* Wed Aug 12 2015 Jan Horak <jhorak@redhat.com> - 40.0-4
+- Workaround for reported crashes (layers.offmainthreadcomposition.enabled set to false)
+
 * Tue Aug 11 2015 Jan Horak <jhorak@redhat.com> - 40.0-3
 - Update to 40.0 Build 5