diff --git a/Documentation/Makefile b/Documentation/Makefile
index 2f6b6aabd7..3e39e2815b 100644
--- a/Documentation/Makefile
+++ b/Documentation/Makefile
@@ -103,7 +103,7 @@ ASCIIDOC_HTML = xhtml11
 ASCIIDOC_DOCBOOK = docbook
 ASCIIDOC_CONF = -f asciidoc.conf
 ASCIIDOC_COMMON = $(ASCIIDOC) $(ASCIIDOC_EXTRA) $(ASCIIDOC_CONF) \
-		-agit-version=$(GIT_VERSION)
+		-agit_version=$(GIT_VERSION)
 TXT_TO_HTML = $(ASCIIDOC_COMMON) -b $(ASCIIDOC_HTML)
 TXT_TO_XML = $(ASCIIDOC_COMMON) -b $(ASCIIDOC_DOCBOOK)
 MANPAGE_XSL = manpage-normal.xsl