diff --git a/minui/graphics.c b/minui/graphics.c
index 296e2e0..81f13ad 100644
--- a/minui/graphics.c
+++ b/minui/graphics.c
@@ -44,6 +44,8 @@
 #define PIXEL_SIZE   2
 #endif
 
+#define NUM_BUFFERS 2
+
 typedef struct {
     GGLSurface texture;
     unsigned cwidth;
@@ -54,7 +56,7 @@
 static GRFont *gr_font = 0;
 static GGLContext *gr_context = 0;
 static GGLSurface gr_font_texture;
-static GGLSurface gr_framebuffer[2];
+static GGLSurface gr_framebuffer[NUM_BUFFERS];
 static GGLSurface gr_mem_surface;
 static unsigned gr_active_fb = 0;
 static unsigned double_buffering = 0;
@@ -169,7 +171,7 @@
 static void set_active_framebuffer(unsigned n)
 {
     if (n > 1 || !double_buffering) return;
-    vi.yres_virtual = vi.yres * PIXEL_SIZE;
+    vi.yres_virtual = vi.yres * NUM_BUFFERS;
     vi.yoffset = n * vi.yres;
     vi.bits_per_pixel = PIXEL_SIZE * 8;
     if (ioctl(gr_fb_fd, FBIOPUT_VSCREENINFO, &vi) < 0) {