diff --git a/lib/redmine/wiki_formatting/markdown/html_parser.rb b/lib/redmine/wiki_formatting/markdown/html_parser.rb
index ff25a0bd2..b9873ba50 100644
--- a/lib/redmine/wiki_formatting/markdown/html_parser.rb
+++ b/lib/redmine/wiki_formatting/markdown/html_parser.rb
@@ -37,7 +37,15 @@ module Redmine
           'h6' => {:pre => "\n\n###### ", :post => "\n\n"},
           'th' => {:pre => '*', :post => "*\n"},
           'td' => {:pre => '', :post => "\n"},
-          'a' => lambda {|node| node.content.present? ? %| [#{node.content}](#{node.attributes['href'].value}) | : %| #{node.attributes['href'].value} |}
+          'a' => lambda do |node|
+            if node.content.present? && node.attributes.key?('href')
+              %| [#{node.content}](#{node.attributes['href'].value}) |
+            elsif node.attributes.key?('href')
+              %| #{node.attributes['href'].value} |
+            else
+              %| #{node.content} |
+            end
+          end
         )
       end
     end
diff --git a/lib/redmine/wiki_formatting/textile/html_parser.rb b/lib/redmine/wiki_formatting/textile/html_parser.rb
index 8623c2068..3f0977bef 100644
--- a/lib/redmine/wiki_formatting/textile/html_parser.rb
+++ b/lib/redmine/wiki_formatting/textile/html_parser.rb
@@ -37,7 +37,15 @@ module Redmine
           'h6' => {:pre => "\n\nh6. ", :post => "\n\n"},
           'th' => {:pre => '*', :post => "*\n"},
           'td' => {:pre => '', :post => "\n"},
-          'a' => lambda {|node| node.content.present? ? %| "#{node.content}":#{node.attributes['href'].value} | : %| #{node.attributes['href'].value} |}
+          'a' => lambda do |node|
+            if node.content.present? && node.attributes.key?('href')
+              %| "#{node.content}":#{node.attributes['href'].value} |
+            elsif node.attributes.key?('href')
+              %| #{node.attributes['href'].value} |
+            else
+              %| #{node.content} |
+            end
+          end
         )
       end
     end