diff --git a/doc/asn1c-usage.lyx b/doc/asn1c-usage.lyx
index a97f3a5..438e7b0 100644
--- a/doc/asn1c-usage.lyx
+++ b/doc/asn1c-usage.lyx
@@ -55,7 +55,7 @@
 \layout Standard
 
 \backslash 
-extramarks{Document revision $Revision$}{}
+extramarks{$Revision$}{}
 \end_inset