diff --git a/ubb-la/gui.c b/ubb-la/gui.c
index e6323ba..e7834f3 100644
--- a/ubb-la/gui.c
+++ b/ubb-la/gui.c
@@ -19,6 +19,13 @@
 #include "gui.h"
 
 
+#if 0
+#define	DEBUG(fmt, ...)	fprintf(stderr, fmt, __VA_ARGS__)
+#else
+#define	DEBUG(fmt, ...)
+#endif
+
+
 #define XRES	320	/* canvas width */
 #define YRES	240	/* canvas height */
 
@@ -98,8 +105,8 @@ static void show_buffer_zoom_in(const uint8_t *buf, int skip, int nibbles,
 	int last[4] = { -1, -1, -1, -1};
 	uint8_t v, bit;
 
-fprintf(stderr, "in: %d-%d (%d) Sa %d-%d (%d) pix %d f (%d)\n",
-    skip, nibbles, nibbles-skip, x0, x1, x1-x0, f, f*(nibbles-skip));
+	DEBUG("in: %d-%d (%d) Sa %d-%d (%d) pix %d f (%d)\n",
+	    skip, nibbles, nibbles-skip, x0, x1, x1-x0, f, f*(nibbles-skip));
 	x = x0;
 	for (i = skip; i != nibbles; i++) {
 		v = (buf[i >> 1] >> 4*(~i & 1)) & 0xf;
@@ -127,8 +134,8 @@ static void show_buffer_zoom_out(const uint8_t *buf, int skip, int nibbles,
 	int changes[4], last[4] = { -1, -1, -1, -1}, next[4];
 	uint8_t v, bit;
 
-fprintf(stderr, "out: %d-%d (%d) Sa %d-%d (%d) pix %d f (%d)\n",
-    skip, nibbles, nibbles-skip, x0, x1, x1-x0, f, f*(x1-x0));
+	DEBUG("out: %d-%d (%d) Sa %d-%d (%d) pix %d f (%d)\n",
+	    skip, nibbles, nibbles-skip, x0, x1, x1-x0, f, f*(x1-x0));
 	for (x = x0; x != x1; x++) {
 		n = i+f;
 		for (j = 0; j != 4; j++) {