diff --git a/changelog.sty b/changelog.sty
index 89dde41..d495f4e 100644
--- a/changelog.sty
+++ b/changelog.sty
@@ -2,7 +2,7 @@
 
 \newcounter{Changelog@Revision}
 
-\def\changelog@base@docnum#1#2#3#4#5R#6#7{#2#3#4#5}
+\def\changelog@base@docnum#1#2#3#4#5R#6{#2#3#4#5}
 \def\changelog@p@docnum{P\expandafter\changelog@base@docnum\wgDocumentNumber}
 \def\changelog@revision@docnum{\changelog@p@docnum R\arabic{Changelog@Revision}}