diff --git a/lib/Makefile.am b/lib/Makefile.am
index 09236ce..0765f03 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -17,12 +17,14 @@
 SUBDIRS += erl
 endif
 
+if ENABLE_RUBY
+SUBDIRS += rb
+endif
+
 EXTRA_DIST = \
   cocoa \
   hs    \
   ocaml \
   perl  \
   php   \
-  rb    \
-  erl   \
   st