diff --git a/mail/Makefile b/mail/Makefile
index 4a1d45af02c1..740f1dbf57a9 100644
--- a/mail/Makefile
+++ b/mail/Makefile
@@ -61,6 +61,7 @@
     SUBDIR += elm
     SUBDIR += elm+ME
     SUBDIR += elmo
+    SUBDIR += elmo-devel
     SUBDIR += emh
     SUBDIR += emh-emacs20
     SUBDIR += emh-xemacs21-mule