diff --git a/tests/suites/test_suite_mdx.function b/tests/suites/test_suite_mdx.function
index 30ca36a0d..dce243ff6 100644
--- a/tests/suites/test_suite_mdx.function
+++ b/tests/suites/test_suite_mdx.function
@@ -1,4 +1,5 @@
 BEGIN_HEADER
+#include <polarssl/config.h>
 #include <polarssl/md2.h>
 #include <polarssl/md4.h>
 #include <polarssl/md5.h>