diff --git a/Source/WebCore/platform/network/NetworkStorageSession.h b/Source/WebCore/platform/network/NetworkStorageSession.h
index 20f53a73e854..bd0dd177b14a 100644
--- a/Source/WebCore/platform/network/NetworkStorageSession.h
+++ b/Source/WebCore/platform/network/NetworkStorageSession.h
@@ -179,7 +179,6 @@ class NetworkStorageSession : public CanMakeWeakPtr<NetworkStorageSession> {
 #if HAVE(COOKIE_CHANGE_LISTENER_API)
     WEBCORE_EXPORT void startListeningForCookieChangeNotifications(CookieChangeObserver&, const String& host);
     WEBCORE_EXPORT void stopListeningForCookieChangeNotifications(CookieChangeObserver&, const HashSet<String>& hosts);
-    WEBCORE_EXPORT bool supportsCookieChangeListenerAPI() const;
 #endif
 
 #if ENABLE(TRACKING_PREVENTION)
diff --git a/Source/WebCore/platform/network/cocoa/NetworkStorageSessionCocoa.mm b/Source/WebCore/platform/network/cocoa/NetworkStorageSessionCocoa.mm
index 0143ce4b5cbc..f1f978d5f0a0 100644
--- a/Source/WebCore/platform/network/cocoa/NetworkStorageSessionCocoa.mm
+++ b/Source/WebCore/platform/network/cocoa/NetworkStorageSessionCocoa.mm
@@ -754,13 +754,6 @@ static NSHTTPCookieAcceptPolicy httpCookieAcceptPolicy(CFHTTPCookieStorageRef co
         [nsCookieStorage() _setSubscribedDomainsForCookieChanges:m_subscribedDomainsForCookieChanges.get()];
 }
 
-// FIXME: This can eventually go away, this is merely to ensure a smooth transition to the new API.
-bool NetworkStorageSession::supportsCookieChangeListenerAPI() const
-{
-    static const bool supportsAPI = [nsCookieStorage() respondsToSelector:@selector(_setCookiesChangedHandler:onQueue:)];
-    return supportsAPI;
-}
-
 #endif // HAVE(COOKIE_CHANGE_LISTENER_API)
 
 } // namespace WebCore
diff --git a/Source/WebKit/WebProcess/WebPage/WebCookieCache.cpp b/Source/WebKit/WebProcess/WebPage/WebCookieCache.cpp
index 2798dcd5655a..b3180076672c 100644
--- a/Source/WebKit/WebProcess/WebPage/WebCookieCache.cpp
+++ b/Source/WebKit/WebProcess/WebPage/WebCookieCache.cpp
@@ -37,8 +37,7 @@ using namespace WebCore;
 bool WebCookieCache::isSupported()
 {
 #if HAVE(COOKIE_CHANGE_LISTENER_API)
-    // FIXME: This can eventually be removed, this is merely to ensure a smooth transition to the new API.
-    return inMemoryStorageSession().supportsCookieChangeListenerAPI();
+    return true;
 #else
     return false;
 #endif