diff --git a/Source/WebKit/ChangeLog b/Source/WebKit/ChangeLog
index ed7f729..d366139 100644
--- a/Source/WebKit/ChangeLog
+++ b/Source/WebKit/ChangeLog
@@ -1,3 +1,18 @@
+2019-10-15  Jiewen Tan  <jiewen_tan@apple.com>
+
+        [WebAuthn] Rename -[WKUIDelegatePrivate webView:runWebAuthenticationPanel:initiatedByFrame:completionHandler:] to -[WKUIDelegatePrivate _webView:runWebAuthenticationPanel:initiatedByFrame:completionHandler:]
+        https://bugs.webkit.org/show_bug.cgi?id=202564
+        <rdar://problem/55974027>
+
+        Reviewed by Brent Fulgham.
+
+        Rename the SPI to a proper SPI style.
+
+        * UIProcess/API/Cocoa/WKUIDelegatePrivate.h:
+        * UIProcess/Cocoa/UIDelegate.mm:
+        (WebKit::UIDelegate::setDelegate):
+        (WebKit::UIDelegate::UIClient::runWebAuthenticationPanel):
+
 2019-10-15  youenn fablet  <youenn@apple.com>
 
         Scheduling a service worker job in server should wait for finishing the registration import
diff --git a/Source/WebKit/UIProcess/API/Cocoa/WKUIDelegatePrivate.h b/Source/WebKit/UIProcess/API/Cocoa/WKUIDelegatePrivate.h
index 9d2a593..7974d0a 100644
--- a/Source/WebKit/UIProcess/API/Cocoa/WKUIDelegatePrivate.h
+++ b/Source/WebKit/UIProcess/API/Cocoa/WKUIDelegatePrivate.h
@@ -137,7 +137,7 @@
 
 - (void)_webView:(WKWebView *)webView takeFocus:(_WKFocusDirection)direction WK_API_AVAILABLE(macos(10.13.4), ios(12.2));
 
-- (void)webView:(WKWebView *)webView runWebAuthenticationPanel:(_WKWebAuthenticationPanel *)panel initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(_WKWebAuthenticationPanelResult))completionHandler WK_API_AVAILABLE(macos(WK_MAC_TBA), ios(WK_IOS_TBA));
+- (void)_webView:(WKWebView *)webView runWebAuthenticationPanel:(_WKWebAuthenticationPanel *)panel initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(_WKWebAuthenticationPanelResult))completionHandler WK_API_AVAILABLE(macos(WK_MAC_TBA), ios(WK_IOS_TBA));
 
 #if TARGET_OS_IPHONE
 - (BOOL)_webView:(WKWebView *)webView shouldIncludeAppLinkActionsForElement:(_WKActivatedElementInfo *)element WK_API_AVAILABLE(ios(9.0));
diff --git a/Source/WebKit/UIProcess/Cocoa/UIDelegate.mm b/Source/WebKit/UIProcess/Cocoa/UIDelegate.mm
index 3ec42ce..50daae36 100644
--- a/Source/WebKit/UIProcess/Cocoa/UIDelegate.mm
+++ b/Source/WebKit/UIProcess/Cocoa/UIDelegate.mm
@@ -174,7 +174,7 @@
     m_delegateMethods.webViewHasVideoInPictureInPictureDidChange = [delegate respondsToSelector:@selector(_webView:hasVideoInPictureInPictureDidChange:)];
     m_delegateMethods.webViewDidShowSafeBrowsingWarning = [delegate respondsToSelector:@selector(_webViewDidShowSafeBrowsingWarning:)];
 #if ENABLE(WEB_AUTHN)
-    m_delegateMethods.webViewRunWebAuthenticationPanelInitiatedByFrameCompletionHandler = [delegate respondsToSelector:@selector(webView:runWebAuthenticationPanel:initiatedByFrame:completionHandler:)];
+    m_delegateMethods.webViewRunWebAuthenticationPanelInitiatedByFrameCompletionHandler = [delegate respondsToSelector:@selector(_webView:runWebAuthenticationPanel:initiatedByFrame:completionHandler:)];
 #endif
 }
 
@@ -1294,8 +1294,8 @@
         return;
     }
 
-    auto checker = CompletionHandlerCallChecker::create(delegate.get(), @selector(webView:runWebAuthenticationPanel:initiatedByFrame:completionHandler:));
-    [(id <WKUIDelegatePrivate>)delegate webView:m_uiDelegate.m_webView runWebAuthenticationPanel:wrapper(panel) initiatedByFrame:nil completionHandler:makeBlockPtr([completionHandler = WTFMove(completionHandler), checker = WTFMove(checker)] (_WKWebAuthenticationPanelResult result) mutable {
+    auto checker = CompletionHandlerCallChecker::create(delegate.get(), @selector(_webView:runWebAuthenticationPanel:initiatedByFrame:completionHandler:));
+    [(id <WKUIDelegatePrivate>)delegate _webView:m_uiDelegate.m_webView runWebAuthenticationPanel:wrapper(panel) initiatedByFrame:nil completionHandler:makeBlockPtr([completionHandler = WTFMove(completionHandler), checker = WTFMove(checker)] (_WKWebAuthenticationPanelResult result) mutable {
         if (checker->completionHandlerHasBeenCalled())
             return;
         checker->didCallCompletionHandler();
diff --git a/Tools/ChangeLog b/Tools/ChangeLog
index 9b92384..dea4dbb 100644
--- a/Tools/ChangeLog
+++ b/Tools/ChangeLog
@@ -1,3 +1,15 @@
+2019-10-15  Jiewen Tan  <jiewen_tan@apple.com>
+
+        [WebAuthn] Rename -[WKUIDelegatePrivate webView:runWebAuthenticationPanel:initiatedByFrame:completionHandler:] to -[WKUIDelegatePrivate _webView:runWebAuthenticationPanel:initiatedByFrame:completionHandler:]
+        https://bugs.webkit.org/show_bug.cgi?id=202564
+        <rdar://problem/55974027>
+
+        Reviewed by Brent Fulgham.
+
+        * TestWebKitAPI/Tests/WebKitCocoa/_WKWebAuthenticationPanel.mm:
+        (-[TestWebAuthenticationPanelUIDelegate _webView:runWebAuthenticationPanel:initiatedByFrame:completionHandler:]):
+        (-[TestWebAuthenticationPanelUIDelegate webView:runWebAuthenticationPanel:initiatedByFrame:completionHandler:]): Deleted.
+
 2019-10-15  Aakash Jain  <aakash_jain@apple.com>
 
         [ews] Use python 3 compatible way to represent octal in buildbot code
diff --git a/Tools/TestWebKitAPI/Tests/WebKitCocoa/_WKWebAuthenticationPanel.mm b/Tools/TestWebKitAPI/Tests/WebKitCocoa/_WKWebAuthenticationPanel.mm
index 8842d9a..184087c 100644
--- a/Tools/TestWebKitAPI/Tests/WebKitCocoa/_WKWebAuthenticationPanel.mm
+++ b/Tools/TestWebKitAPI/Tests/WebKitCocoa/_WKWebAuthenticationPanel.mm
@@ -79,7 +79,7 @@
     return self;
 }
 
-- (void)webView:(WKWebView *)webView runWebAuthenticationPanel:(_WKWebAuthenticationPanel *)panel initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(_WKWebAuthenticationPanelResult))completionHandler
+- (void)_webView:(WKWebView *)webView runWebAuthenticationPanel:(_WKWebAuthenticationPanel *)panel initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(_WKWebAuthenticationPanelResult))completionHandler
 {
     webAuthenticationPanelRan = true;