Note the libotr 4 requirement in the INSTALL file

1d3b1e6f · Ian Goldberg · 26de2a39 · 1d3b1e6f
Commit 1d3b1e6f authored Oct 19, 2014 by Ian Goldberg
--- a/INSTALL
+++ b/INSTALL
@@ -3,7 +3,7 @@ REQUIREMENTS
 To compile the OTR plugin for pidgin, you'll need at least:
 - libgpg-error 1.0  [ftp://ftp.gnupg.org/gcrypt/libgpg-error/]
 - libgcrypt 1.2.0   [ftp://ftp.gnupg.org/gcrypt/libgcrypt/]
- - libotr 3.1.0      [https://otr.cypherpunks.ca/]
+ - libotr 4.0.0      [https://otr.cypherpunks.ca/]
 - glib 2.6          [http://www.gtk.org/download/]
 - gtk+ 2.6          [http://www.gtk.org/download/]
 - pidgin 2.x        [http://pidgin.im/]