diff --git a/scene.cpp b/scene.cpp
--- a/scene.cpp
+++ b/scene.cpp
@@ -898,23 +898,25 @@
         Qt::Horizontal, // Bottom
     };
 
+    const qreal halfPixel = effects->isOpenGLCompositing() ? 0.5 : 0;
+
     for (int i = 0; i < 4; i++) {
         const QRegion intersectedRegion = (region & rects[i]);
         for (const QRect &r : intersectedRegion) {
             if (!r.isValid())
                 continue;
 
             const bool swap = orientations[i] == Qt::Vertical;
 
-            const int x0 = r.x();
-            const int y0 = r.y();
-            const int x1 = r.x() + r.width();
-            const int y1 = r.y() + r.height();
+            const qreal x0 = r.x();
+            const qreal y0 = r.y();
+            const qreal x1 = r.x() + r.width();
+            const qreal y1 = r.y() + r.height();
 
-            const int u0 = (x0 + offsets[i].x()) * textureScale;
-            const int v0 = (y0 + offsets[i].y()) * textureScale;
-            const int u1 = (x1 + offsets[i].x()) * textureScale;
-            const int v1 = (y1 + offsets[i].y()) * textureScale;
+            const qreal u0 = (x0 + offsets[i].x()) * textureScale + halfPixel;
+            const qreal v0 = (y0 + offsets[i].y()) * textureScale + halfPixel;
+            const qreal u1 = (x1 + offsets[i].x()) * textureScale - halfPixel;
+            const qreal v1 = (y1 + offsets[i].y()) * textureScale - halfPixel;
 
             WindowQuad quad(WindowQuadDecoration);
             quad.setUVAxisSwapped(swap);
@@ -956,6 +958,7 @@
 
         ret.append(quad);
     }
+
     return ret;
 }