diff --git a/reference/filesystem/functions/realpath.xml b/reference/filesystem/functions/realpath.xml
index b4014cf395..9ad83b0f2e 100644
--- a/reference/filesystem/functions/realpath.xml
+++ b/reference/filesystem/functions/realpath.xml
@@ -82,6 +82,13 @@
*BSD systems. realpath now fails in this case.
+
+ 5.2.1
+
+ Prior to this version, realpath returned &false;
+ if path is an empty string or &null;.
+
+