diff --git a/source4/lib/registry/man/regdiff.1.xml b/source4/lib/registry/man/regdiff.1.xml
index 3fe965ca5b9..23aae3446dc 100644
--- a/source4/lib/registry/man/regdiff.1.xml
+++ b/source4/lib/registry/man/regdiff.1.xml
@@ -21,10 +21,7 @@
 		<command>regdiff</command>
 		<arg choice="opt">--help</arg>
 		<arg choice="opt">--backend=BACKEND</arg>
-		<arg choice="opt">--backend=BACKEND</arg>
 		<arg choice="opt">--credentials=CREDENTIALS</arg>
-		<arg choice="opt">--credentials=CREDENTIALS</arg>
-		<arg choice="opt">location</arg>
 		<arg choice="opt">location</arg>
 	</cmdsynopsis>
 </refsynopsisdiv>