diff --git a/src/a53f.h b/src/a53f.h
index 14c8a4f..46d4404 100644
--- a/src/a53f.h
+++ b/src/a53f.h
@@ -1,8 +1,8 @@
 #ifndef A53_F_H
 #define A53_F_H
 
-void GSM( u8 *key, int klen, int count, u8 *block1, u8 *block2 );
+void GSM( u8 *key, int klen, int count, u8 *block1, u8 *block2 )  __attribute__((__deprecated__("Deprectaed: use implementation from libosmogsm instead")));
 void ECSD( u8 *key, int klen, int count, u8 *block1, u8 *block2 );
-void GEA3( u8 *key, int klen, u32 input, u8 direction, u8 *block, int m );
+void GEA3( u8 *key, int klen, u32 input, u8 direction, u8 *block, int m ) __attribute__((__deprecated__("Deprectaed: use implementation from libosmogsm instead")));
 
 #endif