Implement md_file in the MD layer
diff --git a/tests/suites/test_suite_md.function b/tests/suites/test_suite_md.function
index a3b87f7..099d109 100644
--- a/tests/suites/test_suite_md.function
+++ b/tests/suites/test_suite_md.function
@@ -68,7 +68,9 @@
 
     TEST_ASSERT( mbedtls_md( NULL, buf, 1, buf ) == MBEDTLS_ERR_MD_BAD_INPUT_DATA );
 
+#if defined(MBEDTLS_FS_IO)
     TEST_ASSERT( mbedtls_md_file( NULL, "", buf ) == MBEDTLS_ERR_MD_BAD_INPUT_DATA );
+#endif
 
     TEST_ASSERT( mbedtls_md_hmac_starts( NULL, buf, 1 )
                  == MBEDTLS_ERR_MD_BAD_INPUT_DATA );