diff --git a/Library/Homebrew/build.rb b/Library/Homebrew/build.rb
index 5953802458..d61c3672a1 100644
--- a/Library/Homebrew/build.rb
+++ b/Library/Homebrew/build.rb
@@ -59,6 +59,8 @@ class Build
         Dependency.prune
       elsif dep.build? && dependent != formula
         Dependency.prune
+      elsif dep.build?
+        Dependency.keep_but_prune_recursive_deps
       end
     end
   end