diff --git a/crypto/ecdh_helper.c b/crypto/ecdh_helper.c
index f05bea5fd257..d3af8e8b0b5e 100644
--- a/crypto/ecdh_helper.c
+++ b/crypto/ecdh_helper.c
@@ -28,7 +28,7 @@ static inline const u8 *ecdh_unpack_data(void *dst, const void *src, size_t sz)
 	return src + sz;
 }
 
-int crypto_ecdh_key_len(const struct ecdh *params)
+unsigned int crypto_ecdh_key_len(const struct ecdh *params)
 {
 	return ECDH_KPP_SECRET_MIN_SIZE + params->key_size;
 }
diff --git a/include/crypto/ecdh.h b/include/crypto/ecdh.h
index 1aff2a8a3a68..d696317c43a8 100644
--- a/include/crypto/ecdh.h
+++ b/include/crypto/ecdh.h
@@ -54,7 +54,7 @@ struct ecdh {
  *
  * Return: size of the key in bytes
  */
-int crypto_ecdh_key_len(const struct ecdh *params);
+unsigned int crypto_ecdh_key_len(const struct ecdh *params);
 
 /**
  * crypto_ecdh_encode_key() - encode the private key