diff --git a/Formula/slony.rb b/Formula/slony.rb
index 7baf95ee308..bbec7e378d7 100644
--- a/Formula/slony.rb
+++ b/Formula/slony.rb
@@ -8,7 +8,9 @@ class Slony < Formula
   depends_on :postgresql
 
   def install
+    postgres = Formula.factory('postgresql')
     system "./configure", "--disable-debug",
+                          "--with-pgconfigdir=#{postgres.opt_prefix}/bin",
                           "--prefix=#{prefix}"
     system "make install"
   end