diff --git a/routers/api/v1/api.go b/routers/api/v1/api.go
index 0238e9a06c0..a77ae9df892 100644
--- a/routers/api/v1/api.go
+++ b/routers/api/v1/api.go
@@ -1514,10 +1514,10 @@ func Routes() *web.Router {
 				m.Get("/signing-key.pub", misc.SigningKeySSH)
 				m.Group("/topics", func() {
 					m.Combo("").Get(repo.ListTopics).
-						Put(reqToken(), reqAdmin(), bind(api.RepoTopicOptions{}), repo.UpdateTopics)
+						Put(reqToken(), reqAdmin(), mustNotBeArchived, bind(api.RepoTopicOptions{}), repo.UpdateTopics)
 					m.Group("/{topic}", func() {
-						m.Combo("").Put(reqToken(), repo.AddTopic).
-							Delete(reqToken(), repo.DeleteTopic)
+						m.Combo("").Put(reqToken(), mustNotBeArchived, repo.AddTopic).
+							Delete(reqToken(), mustNotBeArchived, repo.DeleteTopic)
 					}, reqAdmin())
 				}, reqAnyRepoReader())
 				m.Get("/issue_templates", reqRepoReader(unit.TypeCode), context.ReferencesGitRepo(), repo.GetIssueTemplates)
diff --git a/routers/api/v1/repo/topic.go b/routers/api/v1/repo/topic.go
index 00fef505954..c383c5a1101 100644
--- a/routers/api/v1/repo/topic.go
+++ b/routers/api/v1/repo/topic.go
@@ -100,6 +100,8 @@ func UpdateTopics(ctx *context.APIContext) {
 	//     "$ref": "#/responses/notFound"
 	//   "422":
 	//     "$ref": "#/responses/invalidTopicsError"
+	//   "423":
+	//     "$ref": "#/responses/repoArchivedError"
 
 	form := web.GetForm(ctx).(*api.RepoTopicOptions)
 	topicNames := form.Topics
@@ -161,6 +163,8 @@ func AddTopic(ctx *context.APIContext) {
 	//     "$ref": "#/responses/notFound"
 	//   "422":
 	//     "$ref": "#/responses/invalidTopicsError"
+	//   "423":
+	//     "$ref": "#/responses/repoArchivedError"
 
 	topicName := strings.TrimSpace(strings.ToLower(ctx.PathParam("topic")))
 
@@ -228,6 +232,8 @@ func DeleteTopic(ctx *context.APIContext) {
 	//     "$ref": "#/responses/notFound"
 	//   "422":
 	//     "$ref": "#/responses/invalidTopicsError"
+	//   "423":
+	//     "$ref": "#/responses/repoArchivedError"
 
 	topicName := strings.TrimSpace(strings.ToLower(ctx.PathParam("topic")))
 
diff --git a/templates/swagger/v1_json.tmpl b/templates/swagger/v1_json.tmpl
index 9b2af31f009..8537fd27d67 100644
--- a/templates/swagger/v1_json.tmpl
+++ b/templates/swagger/v1_json.tmpl
@@ -18058,6 +18058,9 @@
           },
           "422": {
             "$ref": "#/responses/invalidTopicsError"
+          },
+          "423": {
+            "$ref": "#/responses/repoArchivedError"
           }
         }
       }
@@ -18104,6 +18107,9 @@
           },
           "422": {
             "$ref": "#/responses/invalidTopicsError"
+          },
+          "423": {
+            "$ref": "#/responses/repoArchivedError"
           }
         }
       },
@@ -18148,6 +18154,9 @@
           },
           "422": {
             "$ref": "#/responses/invalidTopicsError"
+          },
+          "423": {
+            "$ref": "#/responses/repoArchivedError"
           }
         }
       }
diff --git a/templates/swagger/v1_openapi3_json.tmpl b/templates/swagger/v1_openapi3_json.tmpl
index df3cabbac5c..204d9cd845d 100644
--- a/templates/swagger/v1_openapi3_json.tmpl
+++ b/templates/swagger/v1_openapi3_json.tmpl
@@ -30293,6 +30293,9 @@
           },
           "422": {
             "$ref": "#/components/responses/invalidTopicsError"
+          },
+          "423": {
+            "$ref": "#/components/responses/repoArchivedError"
           }
         },
         "summary": "Replace list of topics for a repository",
@@ -30342,6 +30345,9 @@
           },
           "422": {
             "$ref": "#/components/responses/invalidTopicsError"
+          },
+          "423": {
+            "$ref": "#/components/responses/repoArchivedError"
           }
         },
         "summary": "Delete a topic from a repository",
@@ -30389,6 +30395,9 @@
           },
           "422": {
             "$ref": "#/components/responses/invalidTopicsError"
+          },
+          "423": {
+            "$ref": "#/components/responses/repoArchivedError"
           }
         },
         "summary": "Add a topic to a repository",
diff --git a/tests/integration/api_repo_topic_test.go b/tests/integration/api_repo_topic_test.go
index 650e9df4e9d..bd45f0d440d 100644
--- a/tests/integration/api_repo_topic_test.go
+++ b/tests/integration/api_repo_topic_test.go
@@ -186,3 +186,30 @@ func TestAPIRepoTopic(t *testing.T) {
 		AddTokenAuth(token4)
 	MakeRequest(t, req, http.StatusForbidden)
 }
+
+func TestAPIRepoTopicArchived(t *testing.T) {
+	defer tests.PrepareTestEnv(t)()
+
+	user := unittest.AssertExistsAndLoadBean(t, &user_model.User{ID: 30}) // owner of the archived repo51
+	repo := unittest.AssertExistsAndLoadBean(t, &repo_model.Repository{ID: 51})
+	assert.True(t, repo.IsArchived)
+	token := getUserToken(t, user.Name, auth_model.AccessTokenScopeWriteRepository)
+
+	// writing topics on an archived repo must be rejected, matching the web UI
+	req := NewRequestf(t, "PUT", "/api/v1/repos/%s/%s/topics/%s", user.Name, repo.Name, "archivedtopic").
+		AddTokenAuth(token)
+	MakeRequest(t, req, http.StatusLocked)
+
+	req = NewRequestf(t, "DELETE", "/api/v1/repos/%s/%s/topics/%s", user.Name, repo.Name, "archivedtopic").
+		AddTokenAuth(token)
+	MakeRequest(t, req, http.StatusLocked)
+
+	req = NewRequestWithJSON(t, "PUT", fmt.Sprintf("/api/v1/repos/%s/%s/topics", user.Name, repo.Name),
+		&api.RepoTopicOptions{Topics: []string{"archivedtopic"}}).AddTokenAuth(token)
+	MakeRequest(t, req, http.StatusLocked)
+
+	// reading topics stays allowed on an archived repo
+	req = NewRequest(t, "GET", fmt.Sprintf("/api/v1/repos/%s/%s/topics", user.Name, repo.Name)).
+		AddTokenAuth(token)
+	MakeRequest(t, req, http.StatusOK)
+}