diff --git a/activerecord/CHANGELOG.md b/activerecord/CHANGELOG.md
index f208a55d752a0..cda0ab655c70f 100644
--- a/activerecord/CHANGELOG.md
+++ b/activerecord/CHANGELOG.md
@@ -1,3 +1,9 @@
+*   Fix query caching when type information is reset
+
+    Backports ancillary fix in 5.0.
+
+    *James Coleman*
+
 *   Allow `joins` to be unscoped.
 
     Fixes #13775.
diff --git a/activerecord/lib/active_record/type/value.rb b/activerecord/lib/active_record/type/value.rb
index ff99dbc2f19b8..926e95b0c2e32 100644
--- a/activerecord/lib/active_record/type/value.rb
+++ b/activerecord/lib/active_record/type/value.rb
@@ -86,6 +86,11 @@ def ==(other)
           scale == other.scale &&
           limit == other.limit
       end
+      alias eql? ==
+
+      def hash
+        [self.class, precision, scale, limit].hash
+      end
 
       private
 
diff --git a/activerecord/test/cases/query_cache_test.rb b/activerecord/test/cases/query_cache_test.rb
index 9e586a2a9e821..b47d976bbb3d1 100644
--- a/activerecord/test/cases/query_cache_test.rb
+++ b/activerecord/test/cases/query_cache_test.rb
@@ -243,6 +243,26 @@ def test_query_cache_doesnt_leak_cached_results_of_rolled_back_queries
       assert_equal 0, Post.where(title: 'rollback').to_a.count
     end
   end
+
+  def test_query_cached_even_when_types_are_reset
+    Task.cache do
+      # Warm the cache
+      task = Task.find(1)
+
+      Task.connection.type_map.clear
+
+      # Preload the type cache again (so we don't have those queries issued during our assertions)
+      Task.connection.send(:initialize_type_map, Task.connection.type_map)
+
+      # Clear places where type information is cached
+      Task.reset_column_information
+      Task.find_by_statement_cache.clear
+
+      assert_queries(0) do
+        Task.find(1)
+      end
+    end
+  end
 end
 
 class QueryCacheExpiryTest < ActiveRecord::TestCase