diff --git a/Makefile b/Makefile
index 112b364597b8b867a0d3b3126067215e337f4b0b..14b9e4ed177fa842bfe97b8f9be53552ccac8d36 100644
--- a/Makefile
+++ b/Makefile
@@ -15,7 +15,7 @@ md5toc.tar: $(SOURCES)
 	tar -cvf $@ --transform 's|.*|md5toc/&|' $^
 
 md5toc.spec: md5toc.spec.template Makefile
-	sed -e 's/__MD5TOC_VERSION__/$(MD5TOC_VERSION)/' $< > $@
+	sed -e 's/__MD5TOC_VERSION__/$(MD5TOC_VERSION)/;s/-/_/g' $< > $@
 
 srpm:	md5toc.spec md5toc.tar Makefile
 	rpmbuild --define "_topdir $$(pwd)" \
diff --git a/md5toc.spec.template b/md5toc.spec.template
index 9c49340563c3d486ba94a58c513bcfabfdc46dbf..dd81743add0c8dd96c4f329b5b0bcb9c42955427 100644
--- a/md5toc.spec.template
+++ b/md5toc.spec.template
@@ -14,7 +14,7 @@ A simple utility to create a TOC of a directory
 %setup -q -n %{name}
 
 %build
-make
+make -DMD5TOC_VERSION='"__MD5TOC_VERSION__"'
 file md5toc
 
 %install