diff --git a/src/Layers/xrRender_R2/r2.cpp b/src/Layers/xrRender_R2/r2.cpp
index b421826121f..48e6c6b0d22 100644
--- a/src/Layers/xrRender_R2/r2.cpp
+++ b/src/Layers/xrRender_R2/r2.cpp
@@ -79,9 +79,13 @@ static class cl_pos_decompress_params : public R_constant_setup
 {
     virtual void setup(R_constant* C)
     {
-        float VertTan = -1.0f * tanf(deg2rad(Device.fFOV / 2.0f));
-        float HorzTan = -VertTan / Device.fASPECT;
-
+#ifdef USE_OGL
+        const float VertTan = tanf(deg2rad(Device.fFOV / 2.0f));
+        const float HorzTan = VertTan / Device.fASPECT;
+#else
+        const float VertTan = -1.0f * tanf(deg2rad(Device.fFOV / 2.0f));
+        const float HorzTan = -VertTan / Device.fASPECT;
+#endif
         RCache.set_c(
             C, HorzTan, VertTan, (2.0f * HorzTan) / (float)Device.dwWidth, (2.0f * VertTan) / (float)Device.dwHeight);
     }