diff --git a/reference/strings/functions/crypt.xml b/reference/strings/functions/crypt.xml
index 08e6ef940c..0930cb9177 100644
--- a/reference/strings/functions/crypt.xml
+++ b/reference/strings/functions/crypt.xml
@@ -6,6 +6,10 @@
   <refpurpose>One-way string hashing</refpurpose>
  </refnamediv>
  
+ <refsynopsisdiv>
+  &note.not-bin-safe;
+ </refsynopsisdiv>
+ 
  <refsect1 role="description">
   &reftitle.description;
   <methodsynopsis>