diff --git a/Formula/mapnik.rb b/Formula/mapnik.rb
index d183801bc3..ae827b7b34 100644
--- a/Formula/mapnik.rb
+++ b/Formula/mapnik.rb
@@ -9,6 +9,7 @@ class Mapnik < Formula
 
   option 'with-cairo', 'Build with Cairo'
 
+  depends_on :libtool => :build
   depends_on :freetype
   depends_on :libpng
   depends_on 'libtiff'