diff --git a/armsrc/optimized_elite.c b/armsrc/optimized_elite.c
index 3e9e1608a..4fdda62f0 100644
--- a/armsrc/optimized_elite.c
+++ b/armsrc/optimized_elite.c
@@ -153,7 +153,7 @@ Definition 14. Define the rotate key function rk : (F 82 ) 8 × N → (F 82 ) 8
 rk(x [0] . . . x [7] , 0) = x [0] . . . x [7]
 rk(x [0] . . . x [7] , n + 1) = rk(rl(x [0] ) . . . rl(x [7] ), n)
 **/
-static void rk(uint8_t *key, uint8_t n, uint8_t *outp_key) {
+static void rk(const uint8_t *key, uint8_t n, uint8_t *outp_key) {
     memcpy(outp_key, key, 8);
     uint8_t j;
     while (n-- > 0) {
diff --git a/client/src/loclass/elite_crack.c b/client/src/loclass/elite_crack.c
index c5fd2c534..bcd1324ab 100644
--- a/client/src/loclass/elite_crack.c
+++ b/client/src/loclass/elite_crack.c
@@ -158,7 +158,7 @@ Definition 14. Define the rotate key function rk : (F 82 ) 8 × N → (F 82 ) 8
 rk(x [0] . . . x [7] , 0) = x [0] . . . x [7]
 rk(x [0] . . . x [7] , n + 1) = rk(rl(x [0] ) . . . rl(x [7] ), n)
 **/
-static void rk(uint8_t *key, uint8_t n, uint8_t *outp_key) {
+static void rk(const uint8_t *key, uint8_t n, uint8_t *outp_key) {
     memcpy(outp_key, key, 8);
     while (n-- > 0) {
         outp_key[0] = rl(outp_key[0]);