diff --git a/.rubocop_todo.yml b/.rubocop_todo.yml
index 344c609b0..c162bce19 100644
--- a/.rubocop_todo.yml
+++ b/.rubocop_todo.yml
@@ -226,11 +226,6 @@ Style/PercentLiteralDelimiters:
     - 'spec/features/signin_spec.rb'
     - 'spec/features/signout_spec.rb'
 
-# Cop supports --auto-correct.
-Style/PerlBackrefs:
-  Exclude:
-    - 'lib/haml/filters/growstuff_markdown.rb'
-
 # Cop supports --auto-correct.
 # Configuration parameters: EnforcedStyle, SupportedStyles, AllowInnerSlashes.
 # SupportedStyles: slashes, percent_r, mixed
diff --git a/lib/haml/filters/growstuff_markdown.rb b/lib/haml/filters/growstuff_markdown.rb
index e03e8c306..adf4391f6 100644
--- a/lib/haml/filters/growstuff_markdown.rb
+++ b/lib/haml/filters/growstuff_markdown.rb
@@ -2,55 +2,68 @@ require 'bluecloth'
 
 module Haml::Filters
   module GrowstuffMarkdown
+    include Haml::Filters::Base
+
+    def render(text)
+      @expanded = text
+      expand_crops
+      expand_members
+      BlueCloth.new(@expanded).to_html
+    end
+
+    private
+
     CROP_REGEX = /(?<!\\)\[([^\[\]]+?)\]\(crop\)/
     MEMBER_REGEX = /(?<!\\)\[([^\[\]]+?)\]\(member\)/
     MEMBER_AT_REGEX = /(?<!\\)(\@\w+)/
     MEMBER_ESCAPE_AT_REGEX = /(?<!\\)\\(?=\@\w+)/
-    include Haml::Filters::Base
 
-    def render(text)
+    def expand_crops
       # turn [tomato](crop) into [tomato](http://growstuff.org/crops/tomato)
-      expanded = text.gsub(CROP_REGEX) do |m|
-        crop_str = $1
+      @expanded = @expanded.gsub(CROP_REGEX) do |m|
+        crop_str = Regexp.last_match(1)
         # find crop case-insensitively
         crop = Crop.where('lower(name) = ?', crop_str.downcase).first
-        if crop
-          url = Rails.application.routes.url_helpers.crop_url(crop, host: Growstuff::Application.config.host)
-          "[#{crop_str}](#{url})"
-        else
-          crop_str
-        end
+        crop_link crop, crop_str
       end
+    end
 
+    def expand_members
       # turn [jane](member) into [jane](http://growstuff.org/members/jane)
-      expanded = expanded.gsub(MEMBER_REGEX) do |m|
-        member_str = $1
+      @expanded = @expanded.gsub(MEMBER_REGEX) do |m|
+        member_str = Regexp.last_match(1)
         # find member case-insensitively
         member = Member.case_insensitive_login_name(member_str).first
-        if member
-          url = Rails.application.routes.url_helpers.member_url(member, only_path: true)
-          "[#{member_str}](#{url})"
-        else
-          member_str
-        end
+        member_link(member, member_str)
       end
 
       # turn @jane into [@jane](http://growstuff.org/members/jane)
-      expanded = expanded.gsub(MEMBER_AT_REGEX) do |m|
-        member_str = $1
+      @expanded = @expanded.gsub(MEMBER_AT_REGEX) do |m|
+        member_str = Regexp.last_match(1)
         # find member case-insensitively
         member = Member.case_insensitive_login_name(member_str[1..-1]).first
-        if member
-          url = Rails.application.routes.url_helpers.member_url(member, only_path: true)
-          "[#{member_str}](#{url})"
-        else
-          member_str
-        end
+        member_link(member, member_str)
       end
 
-      expanded = expanded.gsub(MEMBER_ESCAPE_AT_REGEX, "")
+      @expanded = @expanded.gsub(MEMBER_ESCAPE_AT_REGEX, "")
+    end
 
-      BlueCloth.new(expanded).to_html
+    def member_link(member, link_text)
+      if member
+        url = Rails.application.routes.url_helpers.member_url(member, only_path: true)
+        "[#{link_text}](#{url})"
+      else
+        member_str
+      end
+    end
+
+    def crop_link(crop, _link_text)
+      if crop
+        url = Rails.application.routes.url_helpers.crop_url(crop, host: Growstuff::Application.config.host)
+        "[#{crop_str}](#{url})"
+      else
+        crop_str
+      end
     end
   end