diff --git a/openstack/compute/v2/extensions/diskconfig/requests.go b/openstack/compute/v2/extensions/diskconfig/requests.go
index 06a922a..cc390f7 100644
--- a/openstack/compute/v2/extensions/diskconfig/requests.go
+++ b/openstack/compute/v2/extensions/diskconfig/requests.go
@@ -45,13 +45,16 @@
 }
 
 // ToServerCreateMap adds the diskconfig option to the base server creation options.
-func (opts CreateOptsExt) ToServerCreateMap() map[string]interface{} {
-	base := opts.CreateOptsBuilder.ToServerCreateMap()
+func (opts CreateOptsExt) ToServerCreateMap() (map[string]interface{}, error) {
+	base, err := opts.CreateOptsBuilder.ToServerCreateMap()
+	if err != nil {
+		return nil, err
+	}
 
 	serverMap := base["server"].(map[string]interface{})
 	serverMap["OS-DCF:diskConfig"] = string(opts.DiskConfig)
 
-	return base
+	return base, nil
 }
 
 // RebuildOptsExt adds a DiskConfig option to the base RebuildOpts.
diff --git a/openstack/compute/v2/extensions/diskconfig/requests_test.go b/openstack/compute/v2/extensions/diskconfig/requests_test.go
index 1f4f626..e3c26d4 100644
--- a/openstack/compute/v2/extensions/diskconfig/requests_test.go
+++ b/openstack/compute/v2/extensions/diskconfig/requests_test.go
@@ -29,7 +29,9 @@
 			}
 		}
 	`
-	th.CheckJSONEquals(t, expected, ext.ToServerCreateMap())
+	actual, err := ext.ToServerCreateMap()
+	th.AssertNoErr(t, err)
+	th.CheckJSONEquals(t, expected, actual)
 }
 
 func TestRebuildOpts(t *testing.T) {