diff --git a/sys/crypto/aesni/aesni_wrap.c b/sys/crypto/aesni/aesni_wrap.c
index 4d2a45b7e4c4..cca69d3d5c96 100644
--- a/sys/crypto/aesni/aesni_wrap.c
+++ b/sys/crypto/aesni/aesni_wrap.c
@@ -147,7 +147,7 @@ aesni_encrypt_ecb(int rounds, const void *key_schedule, size_t len,
 
 void
 aesni_decrypt_ecb(int rounds, const void *key_schedule, size_t len,
-    const uint8_t from[AES_BLOCK_LEN], uint8_t to[AES_BLOCK_LEN])
+    const uint8_t *from, uint8_t *to)
 {
 	__m128i tot;
 	__m128i tout[8];