diff --git a/crc32.h b/crc32.h
new file mode 100644
index 0000000..b1ca28b
--- /dev/null
+++ b/crc32.h
@@ -0,0 +1,20 @@
+/*
+ * efone - Distributed internet phone system.
+ *
+ * (c) 1999,2000 Krzysztof Dabrowski
+ * (c) 1999,2000 ElysiuM deeZine
+ *
+ * This program 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.
+ *
+ */
+
+/* based on implementation by Finn Yannick Jacobs. */
+
+#include <stdint.h>
+
+void chksum_crc32gentab ();
+uint32_t chksum_crc32 (unsigned char *block, unsigned int length);
+extern unsigned int crc_tab[256];