diff --git a/Library/Homebrew/extend/ENV/shared.rb b/Library/Homebrew/extend/ENV/shared.rb
index c07f42edaa..447e4dd295 100644
--- a/Library/Homebrew/extend/ENV/shared.rb
+++ b/Library/Homebrew/extend/ENV/shared.rb
@@ -12,9 +12,9 @@ module SharedEnvExtension
   include CompilerConstants
 
   # @private
-  CC_FLAG_VARS = %w[CFLAGS CXXFLAGS OBJCFLAGS OBJCXXFLAGS]
+  CC_FLAG_VARS = %w[CFLAGS CXXFLAGS OBJCFLAGS OBJCXXFLAGS].freeze
   # @private
-  FC_FLAG_VARS = %w[FCFLAGS FFLAGS]
+  FC_FLAG_VARS = %w[FCFLAGS FFLAGS].freeze
   # @private
   SANITIZED_VARS = %w[
     CDPATH GREP_OPTIONS CLICOLOR_FORCE
@@ -25,7 +25,7 @@ module SharedEnvExtension
     CMAKE_PREFIX_PATH CMAKE_INCLUDE_PATH CMAKE_FRAMEWORK_PATH
     GOBIN GOPATH GOROOT PERL_MB_OPT PERL_MM_OPT
     LIBRARY_PATH
-  ]
+  ].freeze
 
   # @private
   def setup_build_environment(formula = nil)
@@ -193,13 +193,19 @@ module SharedEnvExtension
   def userpaths!
     paths = self["PATH"].split(File::PATH_SEPARATOR)
     # put Superenv.bin and opt path at the first
-    new_paths = paths.select { |p| p.start_with?("#{HOMEBREW_REPOSITORY}/Library/ENV") || p.start_with?("#{HOMEBREW_PREFIX}/opt") }
+    new_paths = paths.select { |p| p.start_with?("#{HOMEBREW_REPOSITORY}/Library/ENV", "#{HOMEBREW_PREFIX}/opt") }
     # XXX hot fix to prefer brewed stuff (e.g. python) over /usr/bin.
     new_paths << "#{HOMEBREW_PREFIX}/bin"
     # reset of self["PATH"]
     new_paths += paths
     # user paths
-    new_paths += ORIGINAL_PATHS.map { |p| p.realpath.to_s rescue nil } - %w[/usr/X11/bin /opt/X11/bin]
+    new_paths += ORIGINAL_PATHS.map do |p|
+      begin
+        p.realpath.to_s
+      rescue
+        nil
+      end
+    end - %w[/usr/X11/bin /opt/X11/bin]
     self["PATH"] = new_paths.uniq.join(File::PATH_SEPARATOR)
   end