2 files changed, 26 insertions, 9 deletions
diff --git a/activerecord/lib/active_record/relation/finder_methods.rb b/activerecord/lib/active_record/relation/finder_methods.rb
index 2dd1e6f14b..01d46f7676 100644
--- a/activerecord/lib/active_record/relation/finder_methods.rb
+++ b/activerecord/lib/active_record/relation/finder_methods.rb
@@ -311,9 +311,9 @@ module ActiveRecord
       conditions = " [#{conditions}]" if conditions
 
       if Array(ids).size == 1
-        error = "Couldn't find #{@klass.name} with #{primary_key}=#{ids}#{conditions}"
+        error = "Couldn't find #{@klass.name} with '#{primary_key}'=#{ids}#{conditions}"
       else
-        error = "Couldn't find all #{@klass.name.pluralize} with IDs "
+        error = "Couldn't find all #{@klass.name.pluralize} with '#{primary_key}': "
         error << "(#{ids.join(", ")})#{conditions} (found #{result_size} results, but was looking for #{expected_size})"
       end
 
diff --git a/activerecord/test/cases/finder_test.rb b/activerecord/test/cases/finder_test.rb
index 47c2217161..b1eded6494 100644
--- a/activerecord/test/cases/finder_test.rb
+++ b/activerecord/test/cases/finder_test.rb
@@ -951,14 +951,23 @@ class FinderTest < ActiveRecord::TestCase
   end
 
   def test_find_one_message_with_custom_primary_key
-    Toy.primary_key = :name
-    begin
-      Toy.find 'Hello World!'
-    rescue ActiveRecord::RecordNotFound => e
-      assert_equal 'Couldn\'t find Toy with name=Hello World!', e.message
+    table_with_custom_primary_key do |model|
+      model.primary_key = :name
+      e = assert_raises(ActiveRecord::RecordNotFound) do
+        model.find 'Hello World!'
+      end
+      assert_equal %Q{Couldn't find MercedesCar with 'name'=Hello World!}, e.message
+    end
+  end
+
+  def test_find_some_message_with_custom_primary_key
+    table_with_custom_primary_key do |model|
+      model.primary_key = :name
+      e = assert_raises(ActiveRecord::RecordNotFound) do
+        model.find 'Hello', 'World!'
+      end
+      assert_equal %Q{Couldn't find all MercedesCars with 'name': (Hello, World!) (found 0 results, but was looking for 2)}, e.message
     end
-  ensure
-    Toy.reset_primary_key
   end
 
   def test_find_without_primary_key
@@ -979,4 +988,12 @@ class FinderTest < ActiveRecord::TestCase
         ActiveRecord::Base.send(:replace_bind_variables, statement, vars)
       end
     end
+
+    def table_with_custom_primary_key
+      yield(Class.new(Toy) do
+        def self.name
+          'MercedesCar'
+        end
+      end)
+    end
 end