diff --git a/lib/discourse_api/api/categories.rb b/lib/discourse_api/api/categories.rb
index 41e8268..0437f15 100644
--- a/lib/discourse_api/api/categories.rb
+++ b/lib/discourse_api/api/categories.rb
@@ -68,6 +68,11 @@ def update_category(args = {})
         response["body"]["category"] if response["body"]
       end
 
+      def reorder_categories(args = {})
+        params = API.params(args).required(:mapping)
+        post("/categories/reorder", params)
+      end
+
       def delete_category(id)
         response = delete("/categories/#{id}")
         response[:body]["success"]
diff --git a/spec/discourse_api/api/categories_spec.rb b/spec/discourse_api/api/categories_spec.rb
index f33d22f..6638120 100644
--- a/spec/discourse_api/api/categories_spec.rb
+++ b/spec/discourse_api/api/categories_spec.rb
@@ -182,6 +182,28 @@
     end
   end
 
+  describe "#reorder_categories" do
+    before do
+      stub_post("#{host}/categories/reorder").to_return(
+        body: fixture("notification_success.json"),
+        headers: {
+          content_type: "application/json",
+        },
+      )
+    end
+
+    it "makes a categories reordering request" do
+      payload = { "1": 2, "2": 3, "3": 4, "4": 1 }
+      response = subject.reorder_categories(mapping: payload.to_json)
+      expect(
+        a_post("#{host}/categories/reorder").with(
+          body: "mapping=#{CGI.escape(payload.to_json.to_s)}",
+        ),
+      ).to have_been_made
+      expect(response["success"]).to eq("OK")
+    end
+  end
+
   describe "#category_set_user_notification" do
     before do
       stub_post("#{host}/category/1/notifications").to_return(