diff --git a/github/resource_github_repository.go b/github/resource_github_repository.go
index 688180c256..0a320a8d37 100644
--- a/github/resource_github_repository.go
+++ b/github/resource_github_repository.go
@@ -96,7 +96,7 @@ func resourceGithubRepository() *schema.Resource {
 				Default:  false,
 			},
 			"topics": {
-				Type:     schema.TypeList,
+				Type:     schema.TypeSet,
 				Elem:     &schema.Schema{Type: schema.TypeString},
 				Optional: true,
 			},
@@ -146,7 +146,7 @@ func resourceGithubRepositoryObject(d *schema.ResourceData) *github.Repository {
 		LicenseTemplate:   github.String(d.Get("license_template").(string)),
 		GitignoreTemplate: github.String(d.Get("gitignore_template").(string)),
 		Archived:          github.Bool(d.Get("archived").(bool)),
-		Topics:            expandStringList(d.Get("topics").([]interface{})),
+		Topics:            expandStringList(d.Get("topics").(*schema.Set).List()),
 	}
 }
 
diff --git a/github/resource_github_repository_test.go b/github/resource_github_repository_test.go
index cf9f521379..1884a351fa 100644
--- a/github/resource_github_repository_test.go
+++ b/github/resource_github_repository_test.go
@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"log"
 	"os"
+	"sort"
 	"strings"
 	"testing"
 
@@ -321,7 +322,7 @@ func TestAccGithubRepository_topics(t *testing.T) {
 						Name:        name,
 						Description: description,
 						Homepage:    "http://example.com/",
-						Topics:      []string{"topic1", "topic2"},
+						Topics:      []string{"topic2", "topic1"},
 
 						// non-zero defaults
 						DefaultBranch:    "master",
@@ -482,6 +483,8 @@ func testAccCheckGithubRepositoryAttributes(repo *github.Repository, want *testA
 		if len(want.Topics) != len(repo.Topics) {
 			return fmt.Errorf("got topics %#v; want %#v", repo.Topics, want.Topics)
 		}
+		sort.Strings(repo.Topics)
+		sort.Strings(want.Topics)
 		for i := range want.Topics {
 			if repo.Topics[i] != want.Topics[i] {
 				return fmt.Errorf("got topics %#v; want %#v", repo.Topics, want.Topics)