diff --git a/activesupport/lib/active_support/json/backends/yaml.rb b/activesupport/lib/active_support/json/backends/yaml.rb
index 077eda548a..f9d8fd8e83 100644
--- a/activesupport/lib/active_support/json/backends/yaml.rb
+++ b/activesupport/lib/active_support/json/backends/yaml.rb
@@ -70,9 +70,11 @@ module ActiveSupport
               left_pos.each_with_index do |left, i|
                 scanner.pos = left.succ
                 chunk = scanner.peek(right_pos[i] - scanner.pos + 1)
-                # overwrite the quotes found around the dates with spaces
-                while times.size > 0 && times[0] <= right_pos[i]
-                  chunk.insert(times.shift - scanner.pos - 1, '! ')
+                if ActiveSupport.parse_json_times
+                  # overwrite the quotes found around the dates with spaces
+                  while times.size > 0 && times[0] <= right_pos[i]
+                    chunk.insert(times.shift - scanner.pos - 1, '! ')
+                  end
                 end
                 chunk.gsub!(/\\([\\\/]|u[[:xdigit:]]{4})/) do
                   ustr = $1
diff --git a/activesupport/test/json/decoding_test.rb b/activesupport/test/json/decoding_test.rb
index 24d9f88c09..6b890c7d46 100644
--- a/activesupport/test/json/decoding_test.rb
+++ b/activesupport/test/json/decoding_test.rb
@@ -72,13 +72,11 @@ class TestJSONDecoding < ActiveSupport::TestCase
         end
       end
     end
-  end
 
-  if backends.include?("JSONGem")
-    test "json decodes time json with time parsing disabled" do
+    test "json decodes time json with time parsing disabled with the #{backend} backend" do
       ActiveSupport.parse_json_times = false
       expected = {"a" => "2007-01-01 01:12:34 Z"}
-      ActiveSupport::JSON.with_backend "JSONGem" do
+      ActiveSupport::JSON.with_backend backend do
         assert_equal expected, ActiveSupport::JSON.decode(%({"a": "2007-01-01 01:12:34 Z"}))
       end
     end