diff --git a/lib/des/des.h b/lib/des/des.h
index f6b96a833..c8b946887 100644
--- a/lib/des/des.h
+++ b/lib/des/des.h
@@ -49,35 +49,38 @@ typedef struct des_ks_struct bit_64;
 extern int des_check_key;	/* defaults to false */
 extern int des_rw_mode;		/* defaults to DES_PCBC_MODE */
 
-extern int des_3ecb_encrypt __P((des_cblock *input,des_cblock *output,des_key_schedule ks1,des_key_schedule ks2,int encrypt));
-extern int des_3cbc_encrypt __P((des_cblock *input,des_cblock *output,long length,des_key_schedule sk1,des_key_schedule sk2,des_cblock *ivec1,des_cblock *ivec2,int encrypt));
-extern u_int32_t des_cbc_cksum __P((des_cblock *input,des_cblock *output,long length,des_key_schedule schedule,des_cblock *ivec));
-extern int des_cbc_encrypt __P((des_cblock *input,des_cblock *output,long length,des_key_schedule schedule,des_cblock *ivec,int encrypt));
-extern int des_cfb_encrypt __P((unsigned char *in,unsigned char *out,int numbits,long length,des_key_schedule schedule,des_cblock *ivec,int encrypt));
-extern int des_ecb_encrypt __P((des_cblock *input,des_cblock *output,des_key_schedule ks,int encrypt));
-extern int des_encrypt __P((u_int32_t *input,u_int32_t *output,des_key_schedule ks, int encrypt));
-extern int des_enc_read __P((int fd,char *buf,int len,des_key_schedule sched,des_cblock *iv));
-extern int des_enc_write __P((int fd,char *buf,int len,des_key_schedule sched,des_cblock *iv));
-extern int des_ofb_encrypt __P((unsigned char *in,unsigned char *out,int numbits,long length,des_key_schedule schedule,des_cblock *ivec));
-extern int des_pcbc_encrypt __P((des_cblock *input,des_cblock *output,long length,des_key_schedule schedule,des_cblock *ivec,int encrypt));
+int des_3ecb_encrypt __P((des_cblock *input,des_cblock *output,des_key_schedule ks1,des_key_schedule ks2,int encrypt));
+int des_3cbc_encrypt __P((des_cblock *input,des_cblock *output,long length,des_key_schedule sk1,des_key_schedule sk2,des_cblock *ivec1,des_cblock *ivec2,int encrypt));
+u_int32_t des_cbc_cksum __P((des_cblock *input,des_cblock *output,long length,des_key_schedule schedule,des_cblock *ivec));
+int des_cbc_encrypt __P((des_cblock *input,des_cblock *output,long length,des_key_schedule schedule,des_cblock *ivec,int encrypt));
+int des_cfb_encrypt __P((unsigned char *in,unsigned char *out,int numbits,long length,des_key_schedule schedule,des_cblock *ivec,int encrypt));
+int des_ecb_encrypt __P((des_cblock *input,des_cblock *output,des_key_schedule ks,int encrypt));
+int des_encrypt __P((u_int32_t *input,u_int32_t *output,des_key_schedule ks, int encrypt));
+int des_enc_read __P((int fd,char *buf,int len,des_key_schedule sched,des_cblock *iv));
+int des_enc_write __P((int fd,char *buf,int len,des_key_schedule sched,des_cblock *iv));
+int des_ofb_encrypt __P((unsigned char *in,unsigned char *out,int numbits,long length,des_key_schedule schedule,des_cblock *ivec));
+int des_pcbc_encrypt __P((des_cblock *input,des_cblock *output,long length,des_key_schedule schedule,des_cblock *ivec,int encrypt));
 
-extern void des_set_odd_parity __P((des_cblock *key));
-extern int des_is_weak_key __P((des_cblock *key));
-extern int des_set_key __P((des_cblock *key,des_key_schedule schedule));
-extern int des_key_sched __P((des_cblock *key,des_key_schedule schedule));
-extern void des_fixup_key_parity __P((des_cblock *key));
+void des_set_odd_parity __P((des_cblock *key));
+int des_is_weak_key __P((des_cblock *key));
+int des_set_key __P((des_cblock *key,des_key_schedule schedule));
+int des_key_sched __P((des_cblock *key,des_key_schedule schedule));
 
-extern int des_string_to_key __P((char *str,des_cblock *key));
-extern int des_string_to_2keys __P((char *str,des_cblock *key1,des_cblock *key2));
+int des_string_to_key __P((char *str,des_cblock *key));
+int des_string_to_2keys __P((char *str,des_cblock *key1,des_cblock *key2));
 
-extern void des_set_random_generator_seed __P((des_cblock *seed));
-extern int des_new_random_key __P((des_cblock *key));
-extern void des_init_random_number_generator __P((des_cblock *seed));
-extern int des_random_key __P((des_cblock ret));
-extern int des_read_password __P((des_cblock *key,char *prompt,int verify));
-extern int des_read_2passwords __P((des_cblock *key1,des_cblock *key2,char *prompt,int verify));
-extern int des_read_pw_string __P((char *buf,int length,char *prompt,int verify));
+void des_set_random_generator_seed __P((des_cblock *seed));
+int des_new_random_key __P((des_cblock *key));
+void des_init_random_number_generator __P((des_cblock *seed));
+int des_random_key __P((des_cblock ret));
+int des_read_password __P((des_cblock *key,char *prompt,int verify));
+int des_read_2passwords __P((des_cblock *key1,des_cblock *key2,char *prompt,int verify));
+int des_read_pw_string __P((char *buf,int length,char *prompt,int verify));
 
-extern u_int32_t des_quad_cksum __P((des_cblock *input,des_cblock *output,long length,int out_count,des_cblock *seed));
+u_int32_t des_quad_cksum __P((des_cblock *input,des_cblock *output,long length,int out_count,des_cblock *seed));
+
+/* MIT Link and source compatibility */
+void des_fixup_key_parity __P((des_cblock *key));
+#define des_fixup_key_parity des_set_odd_parity
 
 #endif /* DES_DEFS */