diff --git a/README.md b/README.md
index 8fe7514..399f243 100644
--- a/README.md
+++ b/README.md
@@ -15,8 +15,8 @@ void AES_init_ctx_iv(struct AES_ctx* ctx, const uint8_t* key, const uint8_t* iv)
 void AES_ctx_set_iv(struct AES_ctx* ctx, const uint8_t* iv);
 
 /* Then start encrypting and decrypting with the functions below: */
-void AES_ECB_encrypt(struct AES_ctx* ctx, const uint8_t* buf);
-void AES_ECB_decrypt(struct AES_ctx* ctx, const uint8_t* buf);
+void AES_ECB_encrypt(struct AES_ctx* ctx, uint8_t* buf);
+void AES_ECB_decrypt(struct AES_ctx* ctx, uint8_t* buf);
 
 void AES_CBC_encrypt_buffer(struct AES_ctx* ctx, uint8_t* buf, uint32_t length);
 void AES_CBC_decrypt_buffer(struct AES_ctx* ctx, uint8_t* buf, uint32_t length);