diff --git a/courses/main.doc b/courses/main.adoc
similarity index 100%
rename from courses/main.doc
rename to courses/main.adoc
diff --git a/courses/main.doc.html b/courses/main.adoc.html
similarity index 100%
rename from courses/main.doc.html
rename to courses/main.adoc.html
diff --git a/courses/main.doc.pdf b/courses/main.adoc.pdf
similarity index 100%
rename from courses/main.doc.pdf
rename to courses/main.adoc.pdf