diff --git a/src/helpers/Monitor.cpp b/src/helpers/Monitor.cpp
index 833a7a5a..f626bb3d 100644
--- a/src/helpers/Monitor.cpp
+++ b/src/helpers/Monitor.cpp
@@ -647,7 +647,7 @@ Vector2D CMonitor::middle() {
 void CMonitor::updateMatrix() {
     wlr_matrix_identity(projMatrix.data());
     if (transform != WL_OUTPUT_TRANSFORM_NORMAL) {
-        wlr_matrix_translate(projMatrix.data(), vecTransformedSize.x / 2.0, vecTransformedSize.y / 2.0);
+        wlr_matrix_translate(projMatrix.data(), vecPixelSize.x / 2.0, vecPixelSize.y / 2.0);
         wlr_matrix_transform(projMatrix.data(), transform);
         wlr_matrix_translate(projMatrix.data(), -vecTransformedSize.x / 2.0, -vecTransformedSize.y / 2.0);
     }