diff --git a/CMakeLists.txt b/CMakeLists.txt
index 732a7b68e8..6dbfcc961f 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -184,6 +184,12 @@ endif()
 add_feature_info("XCB-ICCCM" XCB_ICCCM_FOUND "Required for building test applications for KWin")
 add_feature_info("XCB-CURSOR" XCB_CURSOR_FOUND "Required for XCursor support")
 
+set(HAVE_XCB_SYNC TRUE)
+if (XCB_VERSION VERSION_LESS "1.10")
+    set(HAVE_XCB_SYNC FALSE)
+endif()
+add_feature_info("XCB-SYNC" HAVE_XCB_SYNC "XCB Sync version >= 1.10 required for synced window resizing")
+
 feature_summary(WHAT ALL INCLUDE_QUIET_PACKAGES FATAL_ON_MISSING_REQUIRED_PACKAGES)
 
 ########### configure tests ###############
@@ -471,7 +477,6 @@ set(kwin_KDE_LIBS
 
 set(kwin_XLIB_LIBS
     ${X11_X11_LIB}
-    ${X11_Xext_LIB}
     ${X11_ICE_LIB}
     ${X11_SM_LIB}
 )
diff --git a/client.cpp b/client.cpp
index 167bbdd707..74649a3fb3 100644
--- a/client.cpp
+++ b/client.cpp
@@ -57,7 +57,6 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include <QScriptProgram>
 #include <QWhatsThis>
 // XLib
-#include <X11/extensions/sync.h>
 #include <X11/Xutil.h>
 #include <fixx11h.h>
 #include <xcb/xtest.h>
@@ -1989,6 +1988,7 @@ void Client::getIcons()
 
 void Client::getSyncCounter()
 {
+#if HAVE_XCB_SYNC
     if (!Xcb::Extensions::self()->isSyncAvailable())
         return;
 
@@ -2014,13 +2014,17 @@ void Client::getSyncCounter()
             if (!error.isNull()) {
                 syncRequest.alarm = XCB_NONE;
             } else {
-                XSyncAlarmAttributes attrs;
-                XSyncIntToValue(&attrs.trigger.wait_value, 1);
-                XSyncIntToValue(&attrs.delta, 1);
-                XSyncChangeAlarm(display(), syncRequest.alarm, XSyncCADelta | XSyncCAValue, &attrs);
+                xcb_sync_change_alarm_value_list_t value;
+                memset(&value, 0, sizeof(value));
+                value.value.hi = 0;
+                value.value.lo = 1;
+                value.delta.hi = 0;
+                value.delta.lo = 1;
+                xcb_sync_change_alarm_aux(c, syncRequest.alarm, XCB_SYNC_CA_DELTA | XCB_SYNC_CA_VALUE, &value);
             }
         }
     }
+#endif
 }
 
 /**
diff --git a/config-kwin.h.cmake b/config-kwin.h.cmake
index cf6cac2aea..8e8a805891 100644
--- a/config-kwin.h.cmake
+++ b/config-kwin.h.cmake
@@ -14,6 +14,7 @@
 #cmakedefine01 HAVE_XKB
 #cmakedefine01 HAVE_INPUT
 #cmakedefine01 HAVE_XCB_CURSOR
+#cmakedefine01 HAVE_XCB_SYNC
 
 /* Define to 1 if you have the <unistd.h> header file. */
 #cmakedefine HAVE_UNISTD_H 1