diff --git a/lib/vtls/mbedtls.c b/lib/vtls/mbedtls.c
index 7e0760316d..f0900a5af3 100644
--- a/lib/vtls/mbedtls.c
+++ b/lib/vtls/mbedtls.c
@@ -40,6 +40,7 @@
 #include <mbedtls/error.h>
 #include <mbedtls/entropy.h>
 #include <mbedtls/ctr_drbg.h>
+#include <mbedtls/sha256.h>
 
 #include "urldata.h"
 #include "sendf.h"