diff --git a/activesupport/lib/active_support/core_ext/string/starts_ends_with.rb b/activesupport/lib/active_support/core_ext/string/starts_ends_with.rb
index 09f9a188b51ed..bd4f39dd4a982 100644
--- a/activesupport/lib/active_support/core_ext/string/starts_ends_with.rb
+++ b/activesupport/lib/active_support/core_ext/string/starts_ends_with.rb
@@ -20,14 +20,12 @@ def self.append_features(base)
 
         # Does the string start with the specified +prefix+?
         def starts_with?(prefix)
-          prefix = prefix.to_s
           self[0, prefix.length] == prefix
         end
 
         # Does the string end with the specified +suffix+?
         def ends_with?(suffix)
-          suffix = suffix.to_s
-          self[-suffix.length, suffix.length] == suffix      
+          self[-suffix.length, suffix.length] == suffix
         end
       end
     end
diff --git a/activesupport/test/core_ext/string_ext_test.rb b/activesupport/test/core_ext/string_ext_test.rb
index 23251035dc784..084f8611bfaa8 100644
--- a/activesupport/test/core_ext/string_ext_test.rb
+++ b/activesupport/test/core_ext/string_ext_test.rb
@@ -177,6 +177,7 @@ def test_starts_ends_with_alias
     s = "hello"
     assert s.starts_with?('h')
     assert s.starts_with?('hel')
+    assert !s.starts_with?(:hel)
     assert !s.starts_with?('el')
 
     assert s.start_with?('h')
@@ -185,6 +186,7 @@ def test_starts_ends_with_alias
 
     assert s.ends_with?('o')
     assert s.ends_with?('lo')
+    assert !s.ends_with?(:lo)
     assert !s.ends_with?('el')
 
     assert s.end_with?('o')