diff --git a/Source/WebKit2/ChangeLog b/Source/WebKit2/ChangeLog
index 441d22d2efccd223759066e44ff022e99b7ed5e4..a36b0e2a488b3c55fd5a443f6d34499fc8b87522 100644
--- a/Source/WebKit2/ChangeLog
+++ b/Source/WebKit2/ChangeLog
@@ -1,3 +1,12 @@
+2013-12-03  Seokju Kwon  <seokju@webkit.org>
+
+        Debug build fix : Add '<algorithm>' for 'std::is_sorted' after r159965.
+        https://bugs.webkit.org/show_bug.cgi?id=125140
+
+        Reviewed by Csaba Osztrogonác.
+
+        * Shared/APIClient.h:
+
 2013-12-03  Peter Molnar  <pmolnar.u-szeged@partner.samsung.com>
 
         Fix EFL build with INPUT_TYPE_COLOR disabled.
diff --git a/Source/WebKit2/Shared/APIClient.h b/Source/WebKit2/Shared/APIClient.h
index c745c95d6bdfbe338e7eb819eee73b175e8a2c18..0cab142fba499d20116b6814eb2488e76b16bd96 100644
--- a/Source/WebKit2/Shared/APIClient.h
+++ b/Source/WebKit2/Shared/APIClient.h
@@ -29,6 +29,10 @@
 #include "APIClientTraits.h"
 #include <array>
 
+#if !ASSERT_DISABLED
+#include <algorithm> // std::is_sorted
+#endif
+
 // FIXME: Transition all clients from WebKit::APIClient to API::Client.
 namespace API {