diff --git a/include/mbedtls/md4.h b/include/mbedtls/md4.h
index 8ee4e5c..70e11f9 100644
--- a/include/mbedtls/md4.h
+++ b/include/mbedtls/md4.h
@@ -287,6 +287,8 @@
 #undef MBEDTLS_DEPRECATED
 #endif /* !MBEDTLS_DEPRECATED_REMOVED */
 
+#if defined(MBEDTLS_SELF_TEST)
+
 /**
  * \brief          Checkup routine
  *
@@ -299,6 +301,8 @@
  */
 int mbedtls_md4_self_test( int verbose );
 
+#endif /* MBEDTLS_SELF_TEST */
+
 #ifdef __cplusplus
 }
 #endif