Use the inherited fixtures in identity v2.
diff --git a/openstack/identity/v2/extensions/delegate.go b/openstack/identity/v2/extensions/delegate.go
index 77bf7fb..cee275f 100644
--- a/openstack/identity/v2/extensions/delegate.go
+++ b/openstack/identity/v2/extensions/delegate.go
@@ -7,16 +7,6 @@
 	"github.com/rackspace/gophercloud/pagination"
 )
 
-// Extension is a single OpenStack extension.
-type Extension struct {
-	common.Extension
-}
-
-// GetResult wraps a GetResult from common.
-type GetResult struct {
-	common.GetResult
-}
-
 // ExtensionPage is a single page of Extension results.
 type ExtensionPage struct {
 	common.ExtensionPage
@@ -33,47 +23,22 @@
 
 // ExtractExtensions accepts a Page struct, specifically an ExtensionPage struct, and extracts the
 // elements into a slice of Extension structs.
-func ExtractExtensions(page pagination.Page) ([]Extension, error) {
+func ExtractExtensions(page pagination.Page) ([]common.Extension, error) {
 	// Identity v2 adds an intermediate "values" object.
 
-	type extension struct {
-		Updated     string        `mapstructure:"updated"`
-		Name        string        `mapstructure:"name"`
-		Namespace   string        `mapstructure:"namespace"`
-		Alias       string        `mapstructure:"alias"`
-		Description string        `mapstructure:"description"`
-		Links       []interface{} `mapstructure:"links"`
-	}
-
 	var resp struct {
 		Extensions struct {
-			Values []extension `mapstructure:"values"`
+			Values []common.Extension `mapstructure:"values"`
 		} `mapstructure:"extensions"`
 	}
 
 	err := mapstructure.Decode(page.(ExtensionPage).Body, &resp)
-	if err != nil {
-		return nil, err
-	}
-
-	exts := make([]Extension, len(resp.Extensions.Values))
-	for i, original := range resp.Extensions.Values {
-		exts[i] = Extension{common.Extension{
-			Updated:     original.Updated,
-			Name:        original.Name,
-			Namespace:   original.Namespace,
-			Alias:       original.Alias,
-			Description: original.Description,
-			Links:       original.Links,
-		}}
-	}
-
-	return exts, err
+	return resp.Extensions.Values, err
 }
 
 // Get retrieves information for a specific extension using its alias.
-func Get(c *gophercloud.ServiceClient, alias string) GetResult {
-	return GetResult{common.Get(c, alias)}
+func Get(c *gophercloud.ServiceClient, alias string) common.GetResult {
+	return common.Get(c, alias)
 }
 
 // List returns a Pager which allows you to iterate over the full collection of extensions.