diff --git a/src/main_wayland.cpp b/src/main_wayland.cpp
index 7303fb9947..5916984b0d 100644
--- a/src/main_wayland.cpp
+++ b/src/main_wayland.cpp
@@ -272,7 +272,6 @@ int main(int argc, char *argv[])
     // enforce our internal qpa plugin, unfortunately command line switch has precedence
     setenv("QT_QPA_PLATFORM", "wayland-org.kde.kwin.qpa", true);
 
-    qunsetenv("QT_DEVICE_PIXEL_RATIO");
     KWin::ApplicationWayland a(argc, argv);
 
     // reset QT_QPA_PLATFORM so we don't propagate it to our children (e.g. apps launched from the overview effect)
diff --git a/src/main_x11.cpp b/src/main_x11.cpp
index db8e06b7a3..2a76002c63 100644
--- a/src/main_x11.cpp
+++ b/src/main_x11.cpp
@@ -390,7 +390,6 @@ int main(int argc, char *argv[])
     // disable highdpi scaling
     setenv("QT_ENABLE_HIGHDPI_SCALING", "0", true);
 
-    qunsetenv("QT_DEVICE_PIXEL_RATIO");
     qunsetenv("QT_SCALE_FACTOR");
     qunsetenv("QT_SCREEN_SCALE_FACTORS");