diff --git a/lib/rspec/expectations/extensions.rb b/lib/rspec/expectations/extensions.rb
index fba6aeb20..b25d298ac 100644
--- a/lib/rspec/expectations/extensions.rb
+++ b/lib/rspec/expectations/extensions.rb
@@ -1 +1,2 @@
 require 'rspec/expectations/extensions/kernel'
+require 'rspec/expectations/extensions/rspec/core/example_group'
diff --git a/lib/rspec/expectations/extensions/rspec/core/example_group.rb b/lib/rspec/expectations/extensions/rspec/core/example_group.rb
new file mode 100644
index 000000000..179988bdc
--- /dev/null
+++ b/lib/rspec/expectations/extensions/rspec/core/example_group.rb
@@ -0,0 +1,19 @@
+module Rspec
+  module Core
+    class ExampleGroup
+      module BlockAliases
+        alias_method :to,     :should
+        alias_method :to_not, :should_not
+      end
+
+      # Extends the submitted block with aliases to and to_not
+      # for should and should_not. Allows expectations like this:
+      #
+      #   expect { this_block }.to change{this.expression}.from(old_value).to(new_value)
+      #   expect { this_block }.to raise_error
+      def expect(&block)
+        block.extend BlockAliases
+      end
+    end
+  end
+end