diff --git a/client.cpp b/client.cpp
index 89a08ebf6b..fa8fb8a9fb 100644
--- a/client.cpp
+++ b/client.cpp
@@ -54,10 +54,6 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include <QScriptProgram>
 #endif
 #include <QWhatsThis>
-// X
-#ifdef HAVE_XSYNC
-#include <X11/extensions/sync.h>
-#endif
 // system
 #include <unistd.h>
 #include <signal.h>
@@ -142,11 +138,9 @@ Client::Client()
     , m_decoInputExtent()
 {
     // TODO: Do all as initialization
-#ifdef HAVE_XSYNC
-    syncRequest.counter = syncRequest.alarm = None;
+    syncRequest.counter = syncRequest.alarm = XCB_NONE;
     syncRequest.timeout = syncRequest.failsafeTimeout = NULL;
     syncRequest.isPending = false;
-#endif
 
     // Set the initial mapping state
     mapping_state = Withdrawn;
@@ -227,10 +221,8 @@ Client::~Client()
         m_killHelperPID = 0;
     }
     //SWrapper::Client::clientRelease(this);
-#ifdef HAVE_XSYNC
-    if (syncRequest.alarm != None)
-        XSyncDestroyAlarm(display(), syncRequest.alarm);
-#endif
+    if (syncRequest.alarm != XCB_NONE)
+        xcb_sync_destroy_alarm(connection(), syncRequest.alarm);
     assert(!moveResizeMode);
     assert(m_client == XCB_WINDOW_NONE);
     assert(m_wrapper == XCB_WINDOW_NONE);
@@ -2107,7 +2099,6 @@ void Client::getWindowProtocols()
 
 void Client::getSyncCounter()
 {
-#ifdef HAVE_XSYNC
     if (!Xcb::Extensions::self()->isSyncAvailable())
         return;
 
@@ -2121,26 +2112,31 @@ void Client::getSyncCounter()
 
     if (ret == Success && formatRet == 32) {
         syncRequest.counter = *(long*)(propRet);
-        XSyncIntToValue(&syncRequest.value, 0);
-        XSyncValue zero;
-        XSyncIntToValue(&zero, 0);
-        XSyncSetCounter(display(), syncRequest.counter, zero);
-        if (syncRequest.alarm == None) {
-            XSyncAlarmAttributes attrs;
-            attrs.trigger.counter = syncRequest.counter;
-            attrs.trigger.value_type = XSyncRelative;
-            attrs.trigger.test_type = XSyncPositiveTransition;
-            XSyncIntToValue(&attrs.trigger.wait_value, 1);
-            XSyncIntToValue(&attrs.delta, 1);
-            syncRequest.alarm = XSyncCreateAlarm(display(),
-                                          XSyncCACounter | XSyncCAValueType | XSyncCATestType | XSyncCADelta | XSyncCAValue,
-                                          &attrs);
+        syncRequest.value.hi = 0;
+        syncRequest.value.lo = 0;
+        xcb_sync_int64_t zero;
+        zero.hi = 0;
+        zero.lo = 0;
+        auto *c = connection();
+        xcb_sync_set_counter(c, syncRequest.counter, zero);
+        if (syncRequest.alarm == XCB_NONE) {
+            const uint32_t mask = XCB_SYNC_CA_COUNTER | XCB_SYNC_CA_VALUE_TYPE | XCB_SYNC_CA_VALUE | XCB_SYNC_CA_TEST_TYPE | XCB_SYNC_CA_DELTA ;
+            const uint32_t values[] = {
+                syncRequest.counter,
+                XCB_SYNC_VALUETYPE_RELATIVE,
+                0,
+                1,
+                XCB_SYNC_TESTTYPE_POSITIVE_TRANSITION,
+                0,
+                1
+            };
+            syncRequest.alarm = xcb_generate_id(c);
+            xcb_sync_create_alarm(c, syncRequest.alarm, mask, values);
         }
     }
 
     if (ret == Success)
         XFree(propRet);
-#endif
 }
 
 /**
@@ -2148,8 +2144,7 @@ void Client::getSyncCounter()
  */
 void Client::sendSyncRequest()
 {
-#ifdef HAVE_XSYNC
-    if (syncRequest.counter == None || syncRequest.isPending)
+    if (syncRequest.counter == XCB_NONE || syncRequest.isPending)
         return; // do NOT, NEVER send a sync request when there's one on the stack. the clients will just stop respoding. FOREVER! ...
 
     if (!syncRequest.failsafeTimeout) {
@@ -2164,11 +2159,11 @@ void Client::sendSyncRequest()
     // We increment before the notify so that after the notify
     // syncCounterSerial will equal the value we are expecting
     // in the acknowledgement
-    int overflow;
-    XSyncValue one;
-    XSyncIntToValue(&one, 1);
-#undef XSyncValueAdd // It causes a warning :-/
-    XSyncValueAdd(&syncRequest.value, syncRequest.value, one, &overflow);
+    const uint32_t oldLo = syncRequest.value.lo;
+    syncRequest.value.lo++;;
+    if (oldLo > syncRequest.value.lo) {
+        syncRequest.value.hi++;
+    }
 
     // Send the message to client
     XEvent ev;
@@ -2178,13 +2173,12 @@ void Client::sendSyncRequest()
     ev.xclient.message_type = atoms->wm_protocols;
     ev.xclient.data.l[0] = atoms->net_wm_sync_request;
     ev.xclient.data.l[1] = xTime();
-    ev.xclient.data.l[2] = XSyncValueLow32(syncRequest.value);
-    ev.xclient.data.l[3] = XSyncValueHigh32(syncRequest.value);
+    ev.xclient.data.l[2] = syncRequest.value.lo;
+    ev.xclient.data.l[3] = syncRequest.value.hi;
     ev.xclient.data.l[4] = 0;
     syncRequest.isPending = true;
     XSendEvent(display(), window(), False, NoEventMask, &ev);
-    XSync(display(), false);
-#endif
+    Xcb::sync();
 }
 
 void Client::removeSyncSupport()
@@ -2193,12 +2187,10 @@ void Client::removeSyncSupport()
         setReadyForPainting();
         return;
     }
-#ifdef HAVE_XSYNC
     syncRequest.isPending = false;
-    syncRequest.counter = syncRequest.alarm = None;
+    syncRequest.counter = syncRequest.alarm = XCB_NONE;
     delete syncRequest.timeout; delete syncRequest.failsafeTimeout;
     syncRequest.timeout = syncRequest.failsafeTimeout = NULL;
-#endif
 }
 
 bool Client::wantsTabFocus() const
diff --git a/client.h b/client.h
index 068419ff2c..4d76eec9eb 100644
--- a/client.h
+++ b/client.h
@@ -34,11 +34,9 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 // Qt
 #include <QPixmap>
 // X
-#ifdef HAVE_XSYNC
-#include <X11/extensions/sync.h>
-#endif
 #include <X11/Xutil.h>
 #include <fixx11h.h>
+#include <xcb/sync.h>
 
 // TODO: Cleanup the order of things in this .h file
 
@@ -316,9 +314,7 @@ public:
 
     bool windowEvent(xcb_generic_event_t *e);
     virtual bool eventFilter(QObject* o, QEvent* e);
-#ifdef HAVE_XSYNC
     void syncEvent(xcb_sync_alarm_notify_event_t* e);
-#endif
     NET::WindowType windowType(bool direct = false, int supported_types = 0) const;
 
     bool manage(xcb_window_t w, bool isMapped);
@@ -955,15 +951,13 @@ private:
     QRect geom_before_block;
     QRect deco_rect_before_block;
     bool shade_geometry_change;
-#ifdef HAVE_XSYNC
     struct {
-        XSyncCounter counter;
-        XSyncValue value;
-        XSyncAlarm alarm;
+        xcb_sync_counter_t counter;
+        xcb_sync_int64_t value;
+        xcb_sync_alarm_t alarm;
         QTimer *timeout, *failsafeTimeout;
         bool isPending;
     } syncRequest;
-#endif
     int border_left, border_right, border_top, border_bottom;
     int padding_left, padding_right, padding_top, padding_bottom;
     QRegion _mask;
diff --git a/composite.cpp b/composite.cpp
index a2a59c1611..211e036b48 100644
--- a/composite.cpp
+++ b/composite.cpp
@@ -882,7 +882,6 @@ bool Toplevel::compositing() const
 
 void Client::damageNotifyEvent()
 {
-#ifdef HAVE_XSYNC
     if (syncRequest.isPending && isResize()) {
         emit damaged(this, QRect());
         m_isDamaged = true;
@@ -890,13 +889,9 @@ void Client::damageNotifyEvent()
     }
 
     if (!ready_for_painting) { // avoid "setReadyForPainting()" function calling overhead
-        if (syncRequest.counter == None)   // cannot detect complete redraw, consider done now
+        if (syncRequest.counter == XCB_NONE)   // cannot detect complete redraw, consider done now
             setReadyForPainting();
     }
-#else
-    if (!ready_for_painting)
-        setReadyForPainting();
-#endif
 
     Toplevel::damageNotifyEvent();
 }
diff --git a/events.cpp b/events.cpp
index 7fa1d10fa9..8abf14259b 100644
--- a/events.cpp
+++ b/events.cpp
@@ -443,12 +443,10 @@ bool Workspace::workspaceEvent(xcb_generic_event_t *e)
             }
 
         } else if (eventType == Xcb::Extensions::self()->syncAlarmNotifyEvent() && Xcb::Extensions::self()->isSyncAvailable()) {
-#ifdef HAVE_XSYNC
             for (Client *c : clients)
                 c->syncEvent(reinterpret_cast< xcb_sync_alarm_notify_event_t* >(e));
             for (Client *c : desktops)
                 c->syncEvent(reinterpret_cast< xcb_sync_alarm_notify_event_t* >(e));
-#endif
         } else if (eventType == Xcb::Extensions::self()->fixesCursorNotifyEvent() && Xcb::Extensions::self()->isFixesAvailable()) {
             Cursor::self()->notifyCursorChanged(reinterpret_cast<xcb_xfixes_cursor_notify_event_t*>(e)->cursor_serial);
         }
@@ -1530,12 +1528,9 @@ void Client::keyPressEvent(uint key_code)
     Cursor::setPos(pos);
 }
 
-#ifdef HAVE_XSYNC
 void Client::syncEvent(xcb_sync_alarm_notify_event_t* e)
 {
-#warning port XSync to XCB
-#if KWIN_QT5_PORTING
-    if (e->alarm == syncRequest.alarm && XSyncValueEqual(e->counter_value, syncRequest.value)) {
+    if (e->alarm == syncRequest.alarm && e->counter_value.hi == syncRequest.value.hi && e->counter_value.lo == syncRequest.value.lo) {
         setReadyForPainting();
         syncRequest.isPending = false;
         if (syncRequest.failsafeTimeout)
@@ -1547,9 +1542,7 @@ void Client::syncEvent(xcb_sync_alarm_notify_event_t* e)
         } else // setReadyForPainting does as well, but there's a small chance for resize syncs after the resize ended
             addRepaintFull();
     }
-#endif
 }
-#endif
 
 // ****************************************
 // Unmanaged
diff --git a/geometry.cpp b/geometry.cpp
index d5977492cc..4b7ca8ae53 100644
--- a/geometry.cpp
+++ b/geometry.cpp
@@ -1902,9 +1902,7 @@ void Client::setGeometry(int x, int y, int w, int h, ForceGeometry_t force)
             QSize cs = clientSize();
             XMoveResizeWindow(display(), wrapperId(), clientPos().x(), clientPos().y(),
                               cs.width(), cs.height());
-#ifdef HAVE_XSYNC
-            if (!isResize() || syncRequest.counter == None)
-#endif
+            if (!isResize() || syncRequest.counter == XCB_NONE)
                 XMoveResizeWindow(display(), window(), 0, 0, cs.width(), cs.height());
             // SELI - won't this be too expensive?
             // THOMAS - yes, but gtk+ clients will not resize without ...
@@ -2654,12 +2652,10 @@ void Client::leaveMoveResize()
     m_moveResizeGrabWindow.reset();
     workspace()->setClientIsMoving(0);
     moveResizeMode = false;
-#ifdef HAVE_XSYNC
-    if (syncRequest.counter == None) // don't forget to sanitize since the timeout will no more fire
+    if (syncRequest.counter == XCB_NONE) // don't forget to sanitize since the timeout will no more fire
         syncRequest.isPending = false;
     delete syncRequest.timeout;
     syncRequest.timeout = NULL;
-#endif
 #ifdef KWIN_BUILD_SCREENEDGES
     if (ScreenEdges::self()->isDesktopSwitchingMovingClients())
         ScreenEdges::self()->reserveDesktopSwitching(false, Qt::Vertical|Qt::Horizontal);
@@ -2738,10 +2734,8 @@ void Client::delayedMoveResize()
 
 void Client::handleMoveResize(int x, int y, int x_root, int y_root)
 {
-#ifdef HAVE_XSYNC
     if (syncRequest.isPending && isResize())
         return; // we're still waiting for the client or the timeout
-#endif
 
     if ((mode == PositionCenter && !isMovableAcrossScreens())
             || (mode != PositionCenter && (isShade() || !isResizable())))
@@ -3007,14 +3001,13 @@ void Client::handleMoveResize(int x, int y, int x_root, int y_root)
     if (!update)
         return;
 
-#ifdef HAVE_XSYNC
     if (isResize() && !s_haveResizeEffect) {
         if (!syncRequest.timeout) {
             syncRequest.timeout = new QTimer(this);
             connect(syncRequest.timeout, SIGNAL(timeout()), SLOT(performMoveResize()));
             syncRequest.timeout->setSingleShot(true);
         }
-        if (syncRequest.counter != None) {
+        if (syncRequest.counter != XCB_NONE) {
             syncRequest.timeout->start(250);
             sendSyncRequest();
         } else {                            // for clients not supporting the XSYNC protocol, we
@@ -3023,7 +3016,6 @@ void Client::handleMoveResize(int x, int y, int x_root, int y_root)
         }                                   // and no human can control faster resizes anyway
         XMoveResizeWindow(display(), window(), 0, 0, moveResizeGeom.width() - (border_left + border_right), moveResizeGeom.height() - (border_top + border_bottom));
     } else
-#endif
         performMoveResize();
 
 #ifdef KWIN_BUILD_SCREENEDGES
@@ -3038,13 +3030,11 @@ void Client::performMoveResize()
     if (isMove() || (isResize() && !s_haveResizeEffect)) {
         setGeometry(moveResizeGeom);
     }
-#ifdef HAVE_XSYNC
-    if (syncRequest.counter == None)   // client w/o XSYNC support. allow the next resize event
+    if (syncRequest.counter == XCB_NONE)   // client w/o XSYNC support. allow the next resize event
         syncRequest.isPending = false; // NEVER do this for clients with a valid counter
                                        // (leads to sync request races in some clients)
     if (isResize())
         addRepaintFull();
-#endif
     positionGeometryTip();
     emit clientStepUserMovedResized(this, moveResizeGeom);
 }