diff --git a/src/des/des.c b/src/des/des.c
index b4f7bf6105..7805611967 100644
--- a/src/des/des.c
+++ b/src/des/des.c
@@ -92,7 +92,7 @@ des_ecb_encrypt(void * clear, void * cipher,
 #endif
 #endif
     afs_uint32 P_temp;
-    register unsigned char *P_temp_p = (unsigned char *)&P_temp;
+    volatile unsigned char *P_temp_p = (unsigned char *)&P_temp;
 #ifdef BITS16
     sbox_out S_out;
     afs_uint32 *S_out_p = (afs_uint32 *) & S_out;
diff --git a/src/rxkad/domestic/fcrypt.c b/src/rxkad/domestic/fcrypt.c
index ec336a2245..62f6d82789 100644
--- a/src/rxkad/domestic/fcrypt.c
+++ b/src/rxkad/domestic/fcrypt.c
@@ -112,9 +112,9 @@ fc_ecb_encrypt(void * clear, void * cipher,
 	       fc_KeySchedule schedule, int encrypt)
 {
     afs_uint32 L, R;
-    afs_uint32 S, P;
-    unsigned char *Pchar = (unsigned char *)&P;
-    unsigned char *Schar = (unsigned char *)&S;
+    volatile afs_uint32 S, P;
+    volatile unsigned char *Pchar = (unsigned char *)&P;
+    volatile unsigned char *Schar = (unsigned char *)&S;
     int i;
 
 #if defined(vax) || (defined(mips) && defined(MIPSEL)) || defined(AFSLITTLE_ENDIAN)