diff --git a/admin/environment.xml b/admin/environment.xml
index 019509bf6fb..f60f4ad076a 100644
--- a/admin/environment.xml
+++ b/admin/environment.xml
@@ -46,7 +46,9 @@
       <VENDOR name="mssql" version="8.0" />
       <VENDOR name="oracle" version="9.0" />
     </DATABASE>
-    <PHP version="4.3.0" level="required" />
+    <PHP version="4.3.0" level="required">
+      <RESTRICT function="restrict_php50_version" message="php50restricted" />
+    </PHP>
     <PHP_EXTENSIONS>
       <PHP_EXTENSION name="iconv" level="optional">
         <FEEDBACK>