diff --git a/main.h b/main.h
index 2b123615..68cf6d1a 100644
--- a/main.h
+++ b/main.h
@@ -88,6 +88,7 @@ void update_rs(unsigned char parity[32], unsigned char c);
 void write_little_endian(unsigned int word, int num_bytes, FILE *wav_file);
 static int init_rf();
 extern int Encode_8b10b[][256];
+extern const unsigned char ALPHA_TO[];
 // const unsigned char *CCodecAO40::encode(unsigned char *source_bytes, int byte_count);
 void program_radio();