diff --git a/Source/WebKit/ChangeLog b/Source/WebKit/ChangeLog
index 919bb05..0654db8 100644
--- a/Source/WebKit/ChangeLog
+++ b/Source/WebKit/ChangeLog
@@ -1,3 +1,19 @@
+2019-10-22  youenn fablet  <youenn@apple.com>
+
+        Remove the ability to fallback to custom scheme handlers after a service worker did not handle the load
+        https://bugs.webkit.org/show_bug.cgi?id=203239
+
+        Reviewed by Alex Christensen.
+
+        We remove the ability for service workers to intercept custom scheme handlers.
+        We can then remove the ability for loads that are not handled by service workers to go through custom scheme handlers.
+
+        * WebProcess/Network/WebLoaderStrategy.cpp:
+        (WebKit::WebLoaderStrategy::scheduleLoad):
+        (WebKit::WebLoaderStrategy::scheduleLoadFromNetworkProcess):
+        * WebProcess/Network/WebResourceLoader.cpp:
+        (WebKit::WebResourceLoader::serviceWorkerDidNotHandle):
+
 2019-10-22  Carlos Garcia Campos  <cgarcia@igalia.com>
 
         Unreviewed. Update OptionsGTK.cmake and NEWS for 2.27.2 release
diff --git a/Source/WebKit/WebProcess/Network/WebLoaderStrategy.cpp b/Source/WebKit/WebProcess/Network/WebLoaderStrategy.cpp
index 4688fec..a95f7c1 100644
--- a/Source/WebKit/WebProcess/Network/WebLoaderStrategy.cpp
+++ b/Source/WebKit/WebProcess/Network/WebLoaderStrategy.cpp
@@ -214,17 +214,7 @@
     }
 #endif
 
-#if ENABLE(SERVICE_WORKER)
-    auto url = resourceLoader.request().url();
-    auto* data = url.string().utf8().data();
-    if (data)
-        url.string();
-
-    bool canbeLoadedThroughServiceWorkers = resourceLoader.options().serviceWorkersMode != ServiceWorkersMode::None && (resourceLoader.options().serviceWorkerRegistrationIdentifier || resourceLoader.options().mode == FetchOptions::Mode::Navigate);
-    if (canbeLoadedThroughServiceWorkers || !tryLoadingUsingURLSchemeHandler(resourceLoader)) {
-#else
     if (!tryLoadingUsingURLSchemeHandler(resourceLoader)) {
-#endif
         RELEASE_LOG_IF_ALLOWED("scheduleLoad: URL will be scheduled with the NetworkProcess (frame = %p, pageID = %" PRIu64 ", frameID = %" PRIu64 ", resourceID = %" PRIu64 ")", resourceLoader.frame(), trackingParameters.pageID.toUInt64(), trackingParameters.frameID.toUInt64(), identifier);
         scheduleLoadFromNetworkProcess(resourceLoader, resourceLoader.request(), trackingParameters, shouldClearReferrerOnHTTPSToHTTPRedirect, maximumBufferingTime(resource));
         return;
@@ -251,10 +241,6 @@
 
 void WebLoaderStrategy::scheduleLoadFromNetworkProcess(ResourceLoader& resourceLoader, const ResourceRequest& request, const WebResourceLoader::TrackingParameters& trackingParameters, bool shouldClearReferrerOnHTTPSToHTTPRedirect, Seconds maximumBufferingTime)
 {
-    auto* webFrameLoaderClient = toWebFrameLoaderClient(resourceLoader.frameLoader()->client());
-    auto* webFrame = webFrameLoaderClient ? webFrameLoaderClient->webFrame() : nullptr;
-    auto* webPage = webFrame ? webFrame->page() : nullptr;
-
     ResourceLoadIdentifier identifier = resourceLoader.identifier();
     ASSERT(identifier);
 
@@ -287,12 +273,7 @@
     loadParameters.isHTTPSUpgradeEnabled = resourceLoader.frame() ? resourceLoader.frame()->settings().HTTPSUpgradeEnabled() : false;
 
 #if ENABLE(SERVICE_WORKER)
-    // In case of URL scheme handler, we will try to load on service workers and if unhandled, fallback to URL scheme handler.
-    if (webPage && webPage->urlSchemeHandlerForScheme(resourceLoader.request().url().protocol().toStringWithoutCopying()))
-        loadParameters.serviceWorkersMode = ServiceWorkersMode::Only;
-    else
-        loadParameters.serviceWorkersMode = resourceLoader.options().serviceWorkersMode;
-
+    loadParameters.serviceWorkersMode = resourceLoader.options().serviceWorkersMode;
     loadParameters.serviceWorkerRegistrationIdentifier = resourceLoader.options().serviceWorkerRegistrationIdentifier;
     loadParameters.httpHeadersToKeep = resourceLoader.options().httpHeadersToKeep;
 #endif
diff --git a/Source/WebKit/WebProcess/Network/WebResourceLoader.cpp b/Source/WebKit/WebProcess/Network/WebResourceLoader.cpp
index 5b3ef23..085d509 100644
--- a/Source/WebKit/WebProcess/Network/WebResourceLoader.cpp
+++ b/Source/WebKit/WebProcess/Network/WebResourceLoader.cpp
@@ -242,22 +242,7 @@
 #if ENABLE(SERVICE_WORKER)
     RELEASE_LOG_IF_ALLOWED("serviceWorkerDidNotHandle: (pageID = %" PRIu64 ", frameID = %" PRIu64 ", resourceID = %" PRIu64 ")", m_trackingParameters.pageID.toUInt64(), m_trackingParameters.frameID.toUInt64(), m_trackingParameters.resourceID);
 
-    if (m_coreLoader->options().serviceWorkersMode != ServiceWorkersMode::Only) {
-        auto* webFrameLoaderClient = toWebFrameLoaderClient(m_coreLoader->frameLoader()->client());
-        auto* webFrame = webFrameLoaderClient ? webFrameLoaderClient->webFrame() : nullptr;
-        auto* webPage = webFrame ? webFrame->page() : nullptr;
-
-        if (auto* handler = webPage->urlSchemeHandlerForScheme(m_coreLoader->request().url().protocol().toStringWithoutCopying())) {
-            RELEASE_LOG_IF_ALLOWED("resource loaded by URL scheme handler: (pageID = %" PRIu64 ", frameID = %" PRIu64 ", resourceID = %" PRIu64 ")", m_trackingParameters.pageID.toUInt64(), m_trackingParameters.frameID.toUInt64(), m_trackingParameters.resourceID);
-
-            auto loader = m_coreLoader;
-            WebProcess::singleton().webLoaderStrategy().remove(m_coreLoader.get());
-
-            handler->startNewTask(*loader);
-            return;
-        }
-    }
-
+    ASSERT(m_coreLoader->options().serviceWorkersMode == ServiceWorkersMode::Only);
     auto error = internalError(m_coreLoader->request().url());
     error.setType(ResourceError::Type::Cancellation);
     m_coreLoader->didFail(error);