diff --git a/src/rendering/hwrenderer/scene/hw_flats.cpp b/src/rendering/hwrenderer/scene/hw_flats.cpp
index 3d1839c85..d53092c01 100644
--- a/src/rendering/hwrenderer/scene/hw_flats.cpp
+++ b/src/rendering/hwrenderer/scene/hw_flats.cpp
@@ -323,7 +323,7 @@ void HWFlat::DrawFlat(HWDrawInfo *di, FRenderState &state, bool translucent)
 	int rel = getExtraLight();
 
 	state.SetNormal(plane.plane.Normal().X, plane.plane.Normal().Z, plane.plane.Normal().Y);
-	double zshift = (plane.plane.Normal().Z > 0.0 ? 0.01f : -0.01f); // The HWPlaneMirrorPortal::DrawPortalStencil() z-fights with flats
+	double zshift = (plane.plane.Normal().Z > 0.0 ? 0.1f : -0.1f); // The HWPlaneMirrorPortal::DrawPortalStencil() z-fights with flats
 
 	SetColor(state, di->Level, di->lightmode, lightlevel, rel, di->isFullbrightScene(), Colormap, alpha);
 	SetFog(state, di->Level, di->lightmode, lightlevel, rel, di->isFullbrightScene(), &Colormap, false);