diff --git a/include/ntfs/debug.h b/include/ntfs/debug.h
index e69de29b..df6b6886 100644
--- a/include/ntfs/debug.h
+++ b/include/ntfs/debug.h
@@ -0,0 +1,87 @@
+/*
+ * debug.h - Debugging output functions. Part of the Linux-NTFS project.
+ *
+ * Copyright (c) 2002 Anton Altaparmakov
+ *
+ * This program/include file is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as published
+ * by the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program/include file is distributed in the hope that it will be
+ * useful, but WITHOUT ANY WARRANTY; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program (in the main directory of the Linux-NTFS
+ * distribution in the file COPYING); if not, write to the Free Software
+ * Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#ifndef _NTFS_DEBUG_H
+#define _NTFS_DEBUG_H
+
+#include "config.h"
+
+#ifdef HAVE_STDIO_H
+#	include <stdio.h>
+#endif
+
+#include "attrib.h"
+
+#ifdef DEBUG
+
+#ifdef HAVE_STDARG_H
+#	include <stdarg.h>
+#endif
+#include <errno.h>
+
+/* Debug output to stderr. To get it run ./configure --enable-debug. */
+
+static __inline__ void Dprintf(const char *fmt, ...)
+{
+	int eo = errno;
+	va_list ap;
+
+	va_start(ap, fmt);
+	vfprintf(stderr, fmt, ap);
+	va_end(ap);
+	errno = eo;
+}
+
+static __inline__ void Dputs(const char *s)
+{
+	int eo = errno;
+	fprintf(stderr, "%s\n", s);
+	errno = eo;
+}
+
+static __inline__ void Dperror(const char *s)
+{
+	int eo = errno;
+	perror(s);
+	errno = eo;
+}
+
+extern void ntfs_debug_runlist_dump(const runlist_element *rl);
+
+#else /* if !DEBUG */
+
+static __inline__ void Dprintf(const char *fmt __attribute__((unused)), ...) {}
+static __inline__ void Dputs(const char *s __attribute__((unused))) {}
+static __inline__ void Dperror(const char *s __attribute__((unused))) {}
+static __inline__ void ntfs_debug_runlist_dump(const runlist_element *rl __attribute__((unused))) {}
+
+#endif /* !DEBUG */
+
+#define NTFS_BUG(msg)							  \
+{									  \
+	int ___i;							  \
+	fprintf(stderr, "libntfs: Bug in %s(): %s\n", __FUNCTION__, msg); \
+	Dputs("Forcing segmentation fault!");				  \
+	___i = ((int*)NULL)[1];						  \
+}
+
+#endif /* defined _NTFS_DEBUG_H */
+