diff --git a/src/plugins/platforms/eglfs/qeglfsbackingstore.cpp b/src/plugins/platforms/eglfs/qeglfsbackingstore.cpp
index eccb7f42c5..e09154bb59 100644
--- a/src/plugins/platforms/eglfs/qeglfsbackingstore.cpp
+++ b/src/plugins/platforms/eglfs/qeglfsbackingstore.cpp
@@ -79,6 +79,9 @@ void QEglFSBackingStore::flush(QWindow *window, const QRegion &region, const QPo
 
     makeCurrent();
 
+    QRectF sr = window->screen()->geometry();
+    glViewport(0, 0, sr.width(), sr.height());
+
 #ifdef QEGL_EXTRA_DEBUG
     qWarning("QEglBackingStore::flush %p", window);
 #endif
@@ -120,7 +123,6 @@ void QEglFSBackingStore::flush(QWindow *window, const QRegion &region, const QPo
     };
 
     QRectF r = window->geometry();
-    QRectF sr = window->screen()->geometry();
 
     GLfloat x1 = (r.left() / sr.width()) * 2 - 1;
     GLfloat x2 = (r.right() / sr.width()) * 2 - 1;