diff --git a/BUILD-SYSTEM.asc b/BUILD-SYSTEM.adoc
similarity index 100%
rename from BUILD-SYSTEM.asc
rename to BUILD-SYSTEM.adoc
diff --git a/Makefile b/Makefile
index 371caa0c..5970ee9e 100644
--- a/Makefile
+++ b/Makefile
@@ -103,9 +103,9 @@ $(FREEDOOM2): wadinfo_phase2.txt subdirs
 	rm -f $@
 	$(DEUTEX) $(DEUTEX_ARGS) -iwad -lumps -patch -flats -sounds -musics -graphics -sprites -levels -build wadinfo_phase2.txt $@
 
-doc: BUILD-SYSTEM.asc README.asc
-	asciidoc BUILD-SYSTEM.asc
-	asciidoc README.asc
+doc: BUILD-SYSTEM.adoc README.adoc
+	asciidoc BUILD-SYSTEM.adoc
+	asciidoc README.adoc
 
 DISTDOCS=COPYING CREDITS README.html
 
diff --git a/README.asc b/README.adoc
similarity index 100%
rename from README.asc
rename to README.adoc