diff --git a/Library/Homebrew/build_environment.rb b/Library/Homebrew/build_environment.rb
index e6dbf9734a..d46e4bfb23 100644
--- a/Library/Homebrew/build_environment.rb
+++ b/Library/Homebrew/build_environment.rb
@@ -6,6 +6,10 @@ class BuildEnvironment
     @procs = Set.new
   end
 
+  def merge(*args)
+    @settings.merge(*args)
+  end
+
   def <<(o)
     case o
     when Proc then @procs << o
@@ -41,7 +45,7 @@ module BuildEnvironmentDSL
     if block_given?
       @env << block
     else
-      settings.each { |s| @env << s }
+      @env.merge(settings)
     end
     @env
   end
diff --git a/Library/Homebrew/options.rb b/Library/Homebrew/options.rb
index d273239bbe..3988085ce6 100644
--- a/Library/Homebrew/options.rb
+++ b/Library/Homebrew/options.rb
@@ -104,7 +104,7 @@ class Options
   end
 
   def concat(o)
-    o.each { |opt| @options << opt }
+    @options.merge(o)
     self
   end