diff --git a/library/md.c b/library/md.c
index 777b43c..4f03acc 100644
--- a/library/md.c
+++ b/library/md.c
@@ -32,6 +32,7 @@
 #if defined(MBEDTLS_MD_C)
 
 #include "mbedtls/md.h"
+#include "mbedtls/platform.h"
 #include "mbedtls/platform_util.h"
 
 #if defined(MBEDTLS_PLATFORM_C)