diff --git a/libretro.cpp b/libretro.cpp
index 81e26c9..75ac97f 100755
--- a/libretro.cpp
+++ b/libretro.cpp
@@ -520,7 +520,7 @@ static Deinterlacer deint;
 #define MEDNAFEN_CORE_GEOMETRY_BASE_H 102
 #define MEDNAFEN_CORE_GEOMETRY_MAX_W 160
 #define MEDNAFEN_CORE_GEOMETRY_MAX_H 102
-#define MEDNAFEN_CORE_GEOMETRY_ASPECT_RATIO (4.0 / 3.0)
+#define MEDNAFEN_CORE_GEOMETRY_ASPECT_RATIO (80.0 / 51.0)
 #define FB_WIDTH 160
 #define FB_HEIGHT 102