--- a/toolkit/xre/nsAppRunner.cpp
+++ b/toolkit/xre/nsAppRunner.cpp
@@ -4788,21 +4788,21 @@ MultiprocessBlockPolicy() {
   if (Preferences::GetDefaultCString("app.update.channel").EqualsLiteral("release") &&
       !IsVistaOrLater()) {
     gMultiprocessBlockPolicy = kE10sDisabledForOperatingSystem;
     return gMultiprocessBlockPolicy;
   }
 #endif
 
   /**
-   * Avoids enabling e10s for OS X 10.6 - 10.8 users (<= Lion) as these
+   * Avoids enabling e10s for OS X 10.6 - 10.8 users (<= Mountain Lion) as these
    * versions will be unsupported soon.
    */
 #if defined(XP_MACOSX)
-  if (!nsCocoaFeatures::OnMountainLionOrLater()) {
+  if (!nsCocoaFeatures::OnMavericksOrLater()) {
     gMultiprocessBlockPolicy = kE10sDisabledForOperatingSystem;
     return gMultiprocessBlockPolicy;
   }
 #endif
 
 #if defined(XP_WIN)
   /**
    * We block on Windows XP if layers acceleration is requested. This is due to