diff --git a/source3/lib/util_str.c b/source3/lib/util_str.c
index 414a87a562c..fc13b75cc57 100644
--- a/source3/lib/util_str.c
+++ b/source3/lib/util_str.c
@@ -1644,6 +1644,24 @@ size_t strlen_m_term(const char *s)
 	return strlen_m(s) + 1;
 }
 
+/*
+ * Weird helper routine for the winreg pipe: If nothing is around, return 0,
+ * if a string is there, include the terminator.
+ */
+
+size_t strlen_m_term_null(const char *s)
+{
+	size_t len;
+	if (!s) {
+		return 0;
+	}
+	len = strlen_m(s);
+	if (len == 0) {
+		return 0;
+	}
+
+	return len+1;
+}
 /**
  Return a RFC2254 binary string representation of a buffer.
  Used in LDAP filters.
diff --git a/source3/librpc/idl/winreg.idl b/source3/librpc/idl/winreg.idl
index e911f475250..a69079bf8e5 100644
--- a/source3/librpc/idl/winreg.idl
+++ b/source3/librpc/idl/winreg.idl
@@ -132,7 +132,7 @@ import "lsa.idl", "initshutdown.idl", "security.idl";
 	);
 
 	typedef struct {
-		[value(strlen_m_term(name)*2)] uint16 length; 
+		[value(strlen_m_term_null(name)*2)] uint16 length; 
 		/* size cannot be auto-set by value() as it is the
 		   amount of space the server is allowed to use for this
 		   string in the reply, not its current size */