diff --git a/Source/WebCore/ChangeLog b/Source/WebCore/ChangeLog
index c5483b5..c7dc2c6 100644
--- a/Source/WebCore/ChangeLog
+++ b/Source/WebCore/ChangeLog
@@ -1,5 +1,13 @@
 2019-10-08  Wenson Hsieh  <wenson_hsieh@apple.com>
 
+        Unreviewed, try to fix the WinCairo build after r250824
+
+        * dom/IdleDeadline.h:
+
+        Add a missing include for <wtf/Ref.h>, such that the adoptRef function is defined.
+
+2019-10-08  Wenson Hsieh  <wenson_hsieh@apple.com>
+
         Unreviewed, try to fix the open source macOS build after r250824
 
         * bindings/js/JSDOMConvertRecord.h:
diff --git a/Source/WebCore/dom/IdleDeadline.h b/Source/WebCore/dom/IdleDeadline.h
index 9fe787f..2e4f287 100644
--- a/Source/WebCore/dom/IdleDeadline.h
+++ b/Source/WebCore/dom/IdleDeadline.h
@@ -27,6 +27,7 @@
 
 #include "DOMHighResTimeStamp.h"
 #include <wtf/MonotonicTime.h>
+#include <wtf/Ref.h>
 #include <wtf/RefCounted.h>
 
 namespace WebCore {