diff --git a/crypto/dh_helper.c b/crypto/dh_helper.c
index 69869dad344a..a413b311e568 100644
--- a/crypto/dh_helper.c
+++ b/crypto/dh_helper.c
@@ -33,7 +33,7 @@ static inline unsigned int dh_data_size(const struct dh *p)
 	return p->key_size + p->p_size + p->g_size;
 }
 
-int crypto_dh_key_len(const struct dh *p)
+unsigned int crypto_dh_key_len(const struct dh *p)
 {
 	return DH_KPP_SECRET_MIN_SIZE + dh_data_size(p);
 }
diff --git a/include/crypto/dh.h b/include/crypto/dh.h
index f638998fb6d0..71e1bb24d79f 100644
--- a/include/crypto/dh.h
+++ b/include/crypto/dh.h
@@ -53,7 +53,7 @@ struct dh {
  *
  * Return: size of the key in bytes
  */
-int crypto_dh_key_len(const struct dh *params);
+unsigned int crypto_dh_key_len(const struct dh *params);
 
 /**
  * crypto_dh_encode_key() - encode the private key