diff --git a/include/polarssl/md4.h b/include/polarssl/md4.h
index c590736..24b90ec 100644
--- a/include/polarssl/md4.h
+++ b/include/polarssl/md4.h
@@ -112,6 +112,13 @@
 void md4_hmac_finish( md4_context *ctx, unsigned char output[16] );
 
 /**
+ * \brief          MD4 HMAC context reset
+ *
+ * \param ctx      HMAC context to be reset
+ */
+void md4_hmac_reset( md4_context *ctx );
+
+/**
  * \brief          Output = HMAC-MD4( hmac key, input buffer )
  *
  * \param key      HMAC secret key