diff --git a/openstack/db/v1/instances/results.go b/openstack/db/v1/instances/results.go
index 46731ef..905b32c 100644
--- a/openstack/db/v1/instances/results.go
+++ b/openstack/db/v1/instances/results.go
@@ -1,11 +1,8 @@
 package instances
 
 import (
-	"fmt"
-	"reflect"
 	"time"
 
-	"github.com/mitchellh/mapstructure"
 	"github.com/gophercloud/gophercloud"
 	"github.com/gophercloud/gophercloud/openstack/db/v1/datastores"
 	"github.com/gophercloud/gophercloud/openstack/db/v1/flavors"
@@ -24,10 +21,10 @@
 // Instance represents a remote MySQL instance.
 type Instance struct {
 	// Indicates the datetime that the instance was created
-	Created time.Time `mapstructure:"-"`
+	Created time.Time `json:"created"`
 
 	// Indicates the most recent datetime that the instance was updated.
-	Updated time.Time `mapstructure:"-"`
+	Updated time.Time `json:"updated"`
 
 	// Indicates the hardware flavor the instance uses.
 	Flavor flavors.Flavor
@@ -80,34 +77,11 @@
 
 // Extract will extract an Instance from various result structs.
 func (r commonResult) Extract() (*Instance, error) {
-	if r.Err != nil {
-		return nil, r.Err
+	var s struct {
+		Instance *Instance `json:"instance"`
 	}
-
-	var response struct {
-		Instance Instance `mapstructure:"instance"`
-	}
-
-	err := mapstructure.Decode(r.Body, &response)
-	val := r.Body.(map[string]interface{})["instance"].(map[string]interface{})
-
-	if t, ok := val["created"].(string); ok && t != "" {
-		creationTime, err := time.Parse(time.RFC3339, t)
-		if err != nil {
-			return &response.Instance, err
-		}
-		response.Instance.Created = creationTime
-	}
-
-	if t, ok := val["updated"].(string); ok && t != "" {
-		updatedTime, err := time.Parse(time.RFC3339, t)
-		if err != nil {
-			return &response.Instance, err
-		}
-		response.Instance.Updated = updatedTime
-	}
-
-	return &response.Instance, err
+	err := r.ExtractInto(&s)
+	return s.Instance, err
 }
 
 // InstancePage represents a single page of a paginated instance collection.
@@ -118,71 +92,30 @@
 // IsEmpty checks to see whether the collection is empty.
 func (page InstancePage) IsEmpty() (bool, error) {
 	instances, err := ExtractInstances(page)
-	if err != nil {
-		return true, err
-	}
-	return len(instances) == 0, nil
+	return len(instances) == 0, err
 }
 
 // NextPageURL will retrieve the next page URL.
 func (page InstancePage) NextPageURL() (string, error) {
-	type resp struct {
-		Links []gophercloud.Link `mapstructure:"instances_links"`
+	var s struct {
+		Links []gophercloud.Link `json:"instances_links"`
 	}
-
-	var r resp
-	err := mapstructure.Decode(page.Body, &r)
+	err := page.ExtractInto(&s)
 	if err != nil {
 		return "", err
 	}
-
-	return gophercloud.ExtractNextURL(r.Links)
+	return gophercloud.ExtractNextURL(s.Links)
 }
 
 // ExtractInstances will convert a generic pagination struct into a more
 // relevant slice of Instance structs.
 func ExtractInstances(page pagination.Page) ([]Instance, error) {
-	casted := page.(InstancePage).Body
-
-	var resp struct {
-		Instances []Instance `mapstructure:"instances"`
+	r := page.(InstancePage)
+	var s struct {
+		Instances []Instance `json:"instances"`
 	}
-
-	if err := mapstructure.Decode(casted, &resp); err != nil {
-		return nil, err
-	}
-
-	var vals []interface{}
-	switch casted.(type) {
-	case map[string]interface{}:
-		vals = casted.(map[string]interface{})["instances"].([]interface{})
-	case map[string][]interface{}:
-		vals = casted.(map[string][]interface{})["instances"]
-	default:
-		return resp.Instances, fmt.Errorf("Unknown type: %v", reflect.TypeOf(casted))
-	}
-
-	for i, v := range vals {
-		val := v.(map[string]interface{})
-
-		if t, ok := val["created"].(string); ok && t != "" {
-			creationTime, err := time.Parse(time.RFC3339, t)
-			if err != nil {
-				return resp.Instances, err
-			}
-			resp.Instances[i].Created = creationTime
-		}
-
-		if t, ok := val["updated"].(string); ok && t != "" {
-			updatedTime, err := time.Parse(time.RFC3339, t)
-			if err != nil {
-				return resp.Instances, err
-			}
-			resp.Instances[i].Updated = updatedTime
-		}
-	}
-
-	return resp.Instances, nil
+	err := r.ExtractInto(&s)
+	return s.Instances, err
 }
 
 // UserRootResult represents the result of an operation to enable the root user.
@@ -192,17 +125,11 @@
 
 // Extract will extract root user information from a UserRootResult.
 func (r UserRootResult) Extract() (*users.User, error) {
-	if r.Err != nil {
-		return nil, r.Err
+	var s struct {
+		User *users.User `json:"user"`
 	}
-
-	var response struct {
-		User users.User `mapstructure:"user"`
-	}
-
-	err := mapstructure.Decode(r.Body, &response)
-
-	return &response.User, err
+	err := r.ExtractInto(&s)
+	return s.User, err
 }
 
 // ActionResult represents the result of action requests, such as: restarting