diff --git a/include/mbedtls/md4.h b/include/mbedtls/md4.h
index dc3c048..ce703c0 100644
--- a/include/mbedtls/md4.h
+++ b/include/mbedtls/md4.h
@@ -288,6 +288,8 @@
 #undef MBEDTLS_DEPRECATED
 #endif /* !MBEDTLS_DEPRECATED_REMOVED */
 
+#if defined(MBEDTLS_SELF_TEST)
+
 /**
  * \brief          Checkup routine
  *
@@ -300,6 +302,8 @@
  */
 int mbedtls_md4_self_test( int verbose );
 
+#endif /* MBEDTLS_SELF_TEST */
+
 #ifdef __cplusplus
 }
 #endif