diff --git a/Formula/z3.rb b/Formula/z3.rb
index 7ee4859d501..3570819a225 100644
--- a/Formula/z3.rb
+++ b/Formula/z3.rb
@@ -13,7 +13,7 @@ class Z3 < Formula
   end
 
   option "without-python", "Build without python 2 support"
-  depends_on :python => :recommended if MacOS.version <= :snow_leopard
+  depends_on "python" => :recommended if MacOS.version <= :snow_leopard
   depends_on :python3 => :optional
 
   def install