diff -r 72543547c646 -r 0dc317b5599d mcabber/configure.ac
--- a/mcabber/configure.ac	Sat May 11 22:36:30 2019 +0200
+++ b/mcabber/configure.ac	Sun May 12 10:10:12 2019 +0200
@@ -219,12 +219,7 @@
     AM_PATH_LIBOTR(4.0.0, [
         AC_DEFINE([HAVE_LIBOTR], 1, [Define if you use libotr])
     ], [
-        AM_PATH_LIBOTR(3.1.0, [
-            AC_DEFINE([HAVE_LIBOTR], 1, [Define if you use libotr])
-            AC_DEFINE([HAVE_LIBOTR3], 1, [Define if you use libotr v3])
-        ], [
-            AC_MSG_ERROR(libotr 3.1.0 or newer is required.)
-        ])
+        AC_MSG_ERROR(libotr 4.0.0 or newer is required.)
     ])
 fi