diff --git a/Library/Homebrew/brew.rb b/Library/Homebrew/brew.rb
index 2deba9a510..15c1ee4ffb 100644
--- a/Library/Homebrew/brew.rb
+++ b/Library/Homebrew/brew.rb
@@ -1,5 +1,9 @@
 std_trap = trap("INT") { exit! 130 } # no backtrace thanks
 
+# check ruby version before requiring any modules.
+RUBY_TWO = RUBY_VERSION.split(".").first.to_i >= 2
+raise "Homebrew must be run under Ruby 2!" unless RUBY_TWO
+
 require "pathname"
 HOMEBREW_LIBRARY_PATH = Pathname.new(__FILE__).realpath.parent
 $:.unshift(HOMEBREW_LIBRARY_PATH.to_s)
diff --git a/Library/Homebrew/dev-cmd/test-bot.rb b/Library/Homebrew/dev-cmd/test-bot.rb
index 509780869d..f2ca5bbf55 100644
--- a/Library/Homebrew/dev-cmd/test-bot.rb
+++ b/Library/Homebrew/dev-cmd/test-bot.rb
@@ -49,22 +49,12 @@ module Homebrew
 
   HOMEBREW_TAP_REGEX = %r{^([\w-]+)/homebrew-([\w-]+)$}
 
-  if ruby_has_encoding?
-    def fix_encoding!(str)
-      # Assume we are starting from a "mostly" UTF-8 string
-      str.force_encoding(Encoding::UTF_8)
-      return str if str.valid_encoding?
-      str.encode!(Encoding::UTF_16, :invalid => :replace)
-      str.encode!(Encoding::UTF_8)
-    end
-  elsif require "iconv"
-    def fix_encoding!(str)
-      Iconv.conv("UTF-8//IGNORE", "UTF-8", str)
-    end
-  else
-    def fix_encoding!(str)
-      str
-    end
+  def fix_encoding!(str)
+    # Assume we are starting from a "mostly" UTF-8 string
+    str.force_encoding(Encoding::UTF_8)
+    return str if str.valid_encoding?
+    str.encode!(Encoding::UTF_16, :invalid => :replace)
+    str.encode!(Encoding::UTF_8)
   end
 
   def resolve_test_tap
@@ -181,7 +171,7 @@ module Homebrew
       verbose = ARGV.verbose?
       # Step may produce arbitrary output and we read it bytewise, so must
       # buffer it as binary and convert to UTF-8 once complete
-      output = ruby_has_encoding? ? "".encode!("BINARY") : ""
+      output = "".encode!("BINARY")
       working_dir = Pathname.new(@command.first == "git" ? @repository : Dir.pwd)
       read, write = IO.pipe
 
@@ -1046,19 +1036,8 @@ module Homebrew
   def sanitize_output_for_xml(output)
     unless output.empty?
       # Remove invalid XML CData characters from step output.
-      if ruby_has_encoding?
-        # This is the regex for valid XML chars, but only works in Ruby 2.0+
-        # /[\x09\x0A\x0D\x20-\uD7FF\uE000-\uFFFD\u{10000}-\u{10FFFF}]/
-        # For 1.9 compatibility, use the inverse of that, which stays under \u10000
-        # invalid_xml_pat = /[\x00-\x08\x0B\x0C\x0E-\x1F\uD800-\uDFFF\uFFFE\uFFFF]/
-        # But Ruby won't allow you to reference surrogates, so we have:
-        invalid_xml_pat = /[\x00-\x08\x0B\x0C\x0E-\x1F\uFFFE\uFFFF]/
-        output = output.gsub(invalid_xml_pat, "\uFFFD")
-      else
-        # Invalid XML chars, as far as single-byte chars go
-        output = output.delete("\x00\x01\x02\x03\x04\x05\x06\x07\x08\x0b\x0c\x0e\x0f" \
-          "\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f")
-      end
+      invalid_xml_pat = /[^\x09\x0A\x0D\x20-\uD7FF\uE000-\uFFFD\u{10000}-\u{10FFFF}]/
+      output = output.gsub(invalid_xml_pat, "\uFFFD")
 
       # Truncate to 1MB to avoid hitting CI limits
       if output.bytesize > MAX_STEP_OUTPUT_SIZE
diff --git a/Library/Homebrew/extend/fileutils.rb b/Library/Homebrew/extend/fileutils.rb
index 86abcee853..2b5dcfef32 100644
--- a/Library/Homebrew/extend/fileutils.rb
+++ b/Library/Homebrew/extend/fileutils.rb
@@ -65,8 +65,7 @@ module FileUtils
                    Process.gid
                  end
       begin
-        # group_id.to_s makes OS X 10.6.7 (ruby-1.8.7-p174) and earlier happy.
-        chown(nil, group_id.to_s, tmpdir)
+        chown(nil, group_id, tmpdir)
       rescue Errno::EPERM
         opoo "Failed setting group \"#{Etc.getgrgid(group_id).name}\" on #{tmpdir}"
       end
diff --git a/Library/Homebrew/extend/pathname.rb b/Library/Homebrew/extend/pathname.rb
index 2f0ea7e03b..c9cc9d3f3c 100644
--- a/Library/Homebrew/extend/pathname.rb
+++ b/Library/Homebrew/extend/pathname.rb
@@ -445,39 +445,7 @@ class Pathname
     end
   end
 
-  # We redefine these private methods in order to add the /o modifier to
-  # the Regexp literals, which forces string interpolation to happen only
-  # once instead of each time the method is called. This is fixed in 1.9+.
-  if RUBY_VERSION <= "1.8.7"
-    # @private
-    alias_method :old_chop_basename, :chop_basename
-
-    def chop_basename(path)
-      base = File.basename(path)
-      if /\A#{Pathname::SEPARATOR_PAT}?\z/o =~ base
-        return nil
-      else
-        return path[0, path.rindex(base)], base
-      end
-    end
-    private :chop_basename
-
-    # @private
-    alias_method :old_prepend_prefix, :prepend_prefix
-
-    def prepend_prefix(prefix, relpath)
-      if relpath.empty?
-        File.dirname(prefix)
-      elsif /#{SEPARATOR_PAT}/o =~ prefix
-        prefix = File.dirname(prefix)
-        prefix = File.join(prefix, "") if File.basename(prefix + "a") != "a"
-        prefix + relpath
-      else
-        prefix + relpath
-      end
-    end
-    private :prepend_prefix
-  elsif RUBY_VERSION == "2.0.0"
+  if RUBY_VERSION == "2.0.0"
     # https://bugs.ruby-lang.org/issues/9915
     prepend Module.new {
       def inspect
diff --git a/Library/Homebrew/global.rb b/Library/Homebrew/global.rb
index 95aa568b91..8472eba5cb 100644
--- a/Library/Homebrew/global.rb
+++ b/Library/Homebrew/global.rb
@@ -22,16 +22,8 @@ require "config"
 
 HOMEBREW_REPOSITORY.extend(GitRepositoryExtension)
 
-if RbConfig.respond_to?(:ruby)
-  RUBY_PATH = Pathname.new(RbConfig.ruby)
-else
-  RUBY_PATH = Pathname.new(RbConfig::CONFIG["bindir"]).join(
-    RbConfig::CONFIG["ruby_install_name"] + RbConfig::CONFIG["EXEEXT"]
-  )
-end
+RUBY_PATH = Pathname.new(RbConfig.ruby)
 RUBY_BIN = RUBY_PATH.dirname
-RUBY_TWO = RUBY_VERSION.split(".").first.to_i >= 2
-raise "Homebrew must be run under Ruby 2!" unless RUBY_TWO
 
 HOMEBREW_USER_AGENT_CURL = ENV["HOMEBREW_USER_AGENT_CURL"]
 HOMEBREW_USER_AGENT_RUBY = "#{ENV["HOMEBREW_USER_AGENT"]} ruby/#{RUBY_VERSION}-p#{RUBY_PATCHLEVEL}"
diff --git a/Library/Homebrew/utils.rb b/Library/Homebrew/utils.rb
index 90469bca92..0a1b5158d5 100644
--- a/Library/Homebrew/utils.rb
+++ b/Library/Homebrew/utils.rb
@@ -561,11 +561,6 @@ def number_readable(number)
   numstr
 end
 
-# True if this version of Ruby supports text encodings in its strings
-def ruby_has_encoding?
-  String.method_defined?(:force_encoding)
-end
-
 # Truncates a text string to fit within a byte size constraint,
 # preserving character encoding validity. The returned string will
 # be not much longer than the specified max_bytes, though the exact
@@ -579,13 +574,8 @@ def truncate_text_to_approximate_size(s, max_bytes, options = {})
 
   glue = "\n[...snip...]\n"
   max_bytes_in = [max_bytes - glue.bytesize, 1].max
-  if ruby_has_encoding?
-    bytes = s.dup.force_encoding("BINARY")
-    glue_bytes = glue.encode("BINARY")
-  else
-    bytes = s
-    glue_bytes = glue
-  end
+  bytes = s.dup.force_encoding("BINARY")
+  glue_bytes = glue.encode("BINARY")
   n_front_bytes = (max_bytes_in * front_weight).floor
   n_back_bytes = max_bytes_in - n_front_bytes
   if n_front_bytes == 0
@@ -599,10 +589,8 @@ def truncate_text_to_approximate_size(s, max_bytes, options = {})
     back = bytes[-n_back_bytes..-1]
   end
   out = front + glue_bytes + back
-  if ruby_has_encoding?
-    out.force_encoding("UTF-8")
-    out.encode!("UTF-16", :invalid => :replace)
-    out.encode!("UTF-8")
-  end
+  out.force_encoding("UTF-8")
+  out.encode!("UTF-16", :invalid => :replace)
+  out.encode!("UTF-8")
   out
 end