diff --git a/library/x509_crt.c b/library/x509_crt.c
index 04822e8..8fd8b86 100644
--- a/library/x509_crt.c
+++ b/library/x509_crt.c
@@ -31,11 +31,7 @@
  *  [SIRO] https://cabforum.org/wp-content/uploads/Chunghwatelecom201503cabforumV4.pdf
  */
 
-#if !defined(MBEDTLS_CONFIG_FILE)
-#include "mbedtls/config.h"
-#else
-#include MBEDTLS_CONFIG_FILE
-#endif
+#include "common.h"
 
 #if defined(MBEDTLS_X509_CRT_PARSE_C)