diff --git a/spec/test/unit/assertions.rb b/spec/test/unit/assertions.rb
new file mode 100644
index 00000000..38c3b204
--- /dev/null
+++ b/spec/test/unit/assertions.rb
@@ -0,0 +1,16 @@
+# This files provides test/unit/assertions for rspec-rails <3.2.0 by
+# aliasing Test::Unit::Assertions to MiniTest::Assertions.
+# When rspec-rails is updated to 3.2.0+ this file should be removed.
+#
+# test/unit/assertions was removed from ruby-core in 2.2.0 (https://bugs.ruby-lang.org/issues/9711).
+# rspec-rails <3.2.0 doesn't handle the removal on rails 4.0.x (fixed in https://github.com/rspec/rspec-rails/pull/1264).
+require 'active_support/deprecation'
+ActiveSupport::Deprecation.warn 'This file should be removed when rspec-rails is updated to 3.2.0+'
+
+require 'minitest/unit'
+
+module Test
+  module Unit
+    Assertions = MiniTest::Assertions
+  end
+end