diff --git a/activesupport/lib/active_support/inflector/transliterate.rb b/activesupport/lib/active_support/inflector/transliterate.rb
index 30a9072ee1f0c..236f2eb628aca 100644
--- a/activesupport/lib/active_support/inflector/transliterate.rb
+++ b/activesupport/lib/active_support/inflector/transliterate.rb
@@ -47,7 +47,7 @@ def parameterize(string, sep = '-')
       # replace accented chars with their ascii equivalents
       parameterized_string = transliterate(string)
       # Turn unwanted chars into the separator
-      parameterized_string.gsub!(/[^a-z0-9\-_\+]+/i, sep)
+      parameterized_string.gsub!(/[^a-z0-9\-_]+/i, sep)
       unless sep.nil? || sep.empty?
         re_sep = Regexp.escape(sep)
         # No more than one of the separator in a row.
diff --git a/activesupport/test/inflector_test_cases.rb b/activesupport/test/inflector_test_cases.rb
index 2fa94b8e9c61b..ebd26d3fc6315 100644
--- a/activesupport/test/inflector_test_cases.rb
+++ b/activesupport/test/inflector_test_cases.rb
@@ -158,7 +158,8 @@ module InflectorTestCases
     "Allow_Under_Scores"                  => "allow_under_scores",
     "Trailing bad characters!@#"          => "trailing-bad-characters",
     "!@#Leading bad characters"           => "leading-bad-characters",
-    "Squeeze   separators"                => "squeeze-separators"
+    "Squeeze   separators"                => "squeeze-separators",
+    "Test with + sign"                    => "test-with-sign"
   }
 
   StringToParameterizeWithNoSeparator = {
@@ -166,7 +167,8 @@ module InflectorTestCases
     "Random text with *(bad)* characters" => "randomtextwithbadcharacters",
     "Trailing bad characters!@#"          => "trailingbadcharacters",
     "!@#Leading bad characters"           => "leadingbadcharacters",
-    "Squeeze   separators"                => "squeezeseparators"
+    "Squeeze   separators"                => "squeezeseparators",
+    "Test with + sign"                    => "testwithsign"
   }
 
   StringToParameterizeWithUnderscore = {
@@ -174,7 +176,8 @@ module InflectorTestCases
     "Random text with *(bad)* characters" => "random_text_with_bad_characters",
     "Trailing bad characters!@#"          => "trailing_bad_characters",
     "!@#Leading bad characters"           => "leading_bad_characters",
-    "Squeeze   separators"                => "squeeze_separators"
+    "Squeeze   separators"                => "squeeze_separators",
+    "Test with + sign"                    => "test_with_sign"
   }
 
   # Ruby 1.9 doesn't do Unicode normalization yet.