diff --git a/include/polarssl/md.h b/include/polarssl/md.h
index 9be55a9..3e6d63f 100644
--- a/include/polarssl/md.h
+++ b/include/polarssl/md.h
@@ -47,6 +47,13 @@
 extern "C" {
 #endif
 
+/**
+ * \brief     Enumeration of supported message digests
+ *
+ * \warning   MD2, MD4, MD5 and SHA-1 are considered weak message digests and
+ *            their use constitutes a security risk. We recommend considering
+ *            stronger message digests instead.
+ */
 typedef enum {
     POLARSSL_MD_NONE=0,
     POLARSSL_MD_MD2,