diff --git a/library/chacha20.c b/library/chacha20.c
index 343b216..bda39b2 100644
--- a/library/chacha20.c
+++ b/library/chacha20.c
@@ -23,11 +23,7 @@
  *  This file is part of mbed TLS (https://tls.mbed.org)
  */
 
-#if !defined(MBEDTLS_CONFIG_FILE)
-#include "mbedtls/config.h"
-#else
-#include MBEDTLS_CONFIG_FILE
-#endif
+#include "common.h"
 
 #if defined(MBEDTLS_CHACHA20_C)