diff --git a/src/routes/getTopCategoryUsers.ts b/src/routes/getTopCategoryUsers.ts
index 74853b3..c8ce0d0 100644
--- a/src/routes/getTopCategoryUsers.ts
+++ b/src/routes/getTopCategoryUsers.ts
@@ -2,10 +2,12 @@ import { db } from "../databases/databases";
 import { createMemoryCache } from "../utils/createMemoryCache";
 import { config } from "../config";
 import { Request, Response } from "express";
+import { validateCategories } from "../utils/parseParams";
 
 const MILLISECONDS_IN_MINUTE = 60000;
 // eslint-disable-next-line @typescript-eslint/no-misused-promises
 const getTopCategoryUsersWithCache = createMemoryCache(generateTopCategoryUsersStats, config.getTopUsersCacheTimeMinutes * MILLISECONDS_IN_MINUTE);
+/* istanbul ignore next */
 const maxRewardTimePerSegmentInSeconds = config.maxRewardTimePerSegmentInSeconds ?? 86400;
 
 interface DBSegment {
@@ -38,7 +40,6 @@ async function generateTopCategoryUsersStats(sortBy: string, category: string) {
         }
     }
 
-
     return {
         userNames,
         viewCounts,
@@ -51,7 +52,7 @@ export async function getTopCategoryUsers(req: Request, res: Response): Promise<
     const sortType = parseInt(req.query.sortType as string);
     const category = req.query.category as string;
 
-    if (sortType == undefined || !config.categoryList.includes(category) ) {
+    if (sortType == undefined || !validateCategories([category]) ) {
         //invalid request
         return res.sendStatus(400);
     }
diff --git a/src/routes/getTotalStats.ts b/src/routes/getTotalStats.ts
index 44b160f..49699c0 100644
--- a/src/routes/getTotalStats.ts
+++ b/src/routes/getTotalStats.ts
@@ -67,7 +67,6 @@ function getStats(countContributingUsers: boolean): Promise<DBStatsData> {
     }
 }
 
-
 function updateExtensionUsers() {
     if (config.userCounterURL) {
         axios.get(`${config.userCounterURL}/api/v1/userCount`)
@@ -87,12 +86,13 @@ function updateExtensionUsers() {
         });
     getCWSUsers(chromeExtId)
         .then(res => chromeUsersCache = res)
-        .catch(() =>
+        .catch(/* istanbul ignore next */ () =>
             getChromeUsers(chromeExtensionUrl)
                 .then(res => chromeUsersCache = res)
         );
 }
 
+/* istanbul ignore next */
 function getChromeUsers(chromeExtensionUrl: string): Promise<number> {
     return axios.get(chromeExtensionUrl)
         .then(res => {
diff --git a/src/utils/parseParams.ts b/src/utils/parseParams.ts
index 258b78a..cb0c93d 100644
--- a/src/utils/parseParams.ts
+++ b/src/utils/parseParams.ts
@@ -73,3 +73,6 @@ export const parseActionTypes = (req: Request, fallback: ActionType[]): ActionTy
 
 export const parseRequiredSegments = (req: Request): SegmentUUID[] | undefined =>
     syntaxErrorWrapper(getRequiredSegments, req, []); // never fall back
+
+export const validateCategories = (categories: string[]): boolean =>
+    categories.every((category: string) => config.categoryList.includes(category));
\ No newline at end of file
diff --git a/test/cases/getSkipSegments.ts b/test/cases/getSkipSegments.ts
index f89b778..275f231 100644
--- a/test/cases/getSkipSegments.ts
+++ b/test/cases/getSkipSegments.ts
@@ -486,4 +486,13 @@ describe("getSkipSegments", () => {
             })
             .catch(err => done(err));
     });
+
+    it("Should get 400 for invalid category type", (done) => {
+        client.get(endpoint, { params: { videoID: "getSkipSegmentID0", category: 1 } })
+            .then(res => {
+                assert.strictEqual(res.status, 400);
+                done();
+            })
+            .catch(err => done(err));
+    });
 });
diff --git a/test/cases/getTopCategoryUsers.ts b/test/cases/getTopCategoryUsers.ts
index f321373..bd8adc4 100644
--- a/test/cases/getTopCategoryUsers.ts
+++ b/test/cases/getTopCategoryUsers.ts
@@ -29,7 +29,7 @@ describe("getTopCategoryUsers", () => {
             .catch(err => done(err));
     });
 
-    it("Should return 400 if invalid sortType provided", (done) => {
+    it("Should return 400 if invalid type of sortType provided", (done) => {
         client.get(endpoint, { params: { sortType: "a" } })
             .then(res => {
                 assert.strictEqual(res.status, 400);
@@ -38,6 +38,15 @@ describe("getTopCategoryUsers", () => {
             .catch(err => done(err));
     });
 
+    it("Should return 400 if invalid sortType number provided", (done) => {
+        client.get(endpoint, { params: { sortType: 15, category: "sponsor" } })
+            .then(res => {
+                assert.strictEqual(res.status, 400);
+                done();
+            })
+            .catch(err => done(err));
+    });
+
     it("Should return 400 if invalid category provided", (done) => {
         client.get(endpoint, { params: { sortType: 1, category: "never_valid_category" } })
             .then(res => {
@@ -121,4 +130,16 @@ describe("getTopCategoryUsers", () => {
             })
             .catch(err => done(err));
     });
+
+    it("Should return no time saved for chapters", (done) => {
+        client.get(endpoint, { params: { sortType: 2, category: "chapter" } })
+            .then(res => {
+                assert.strictEqual(res.status, 200);
+                for (const timeSaved of res.data.minutesSaved) {
+                    assert.strictEqual(timeSaved, 0, "Time saved should be 0");
+                }
+                done();
+            })
+            .catch(err => done(err));
+    });
 });