diff --git a/m4/buddy.m4 b/m4/buddy.m4
index 30f8c65b9..f76859413 100644
--- a/m4/buddy.m4
+++ b/m4/buddy.m4
@@ -2,7 +2,7 @@ AC_DEFUN([AX_CHECK_BUDDY], [
   AC_ARG_WITH([included-buddy],
 	      [AC_HELP_STRING([--with-included-buddy],
 			      [use the BuDDy library included here])])
-  AC_CHECK_LIB([bdd], [bdd_setxor],
+  AC_CHECK_LIB([bdd], [bdd_implies],
 	       [need_included_buddy=no],
 	       [need_included_buddy=yes])