diff --git a/index.js b/index.js
index b26f649..6e68f7a 100644
--- a/index.js
+++ b/index.js
@@ -2,6 +2,7 @@ const express = require('express');
 const axios = require('axios');
 const redis = require('redis');
 const cors = require('cors');
+const { param, validationResult } = require('express-validator');
 const app = express();
 
 const redisConfig = {
@@ -19,7 +20,7 @@ client.on('error', (err) => {
 app.use(cors());
 
 function LeagueSeason(leagueID, year) {
-  this.params = {league: leagueID, season: year}
+  this.params = { league: leagueID, season: year }
   this.headers = {
     'x-rapidapi-host': process.env.API_HOST,
     'x-rapidapi-key': process.env.API_KEY,
@@ -98,39 +99,52 @@ app.get('/championship', async (req, res) => {
   }
 });
 
-app.get('/v2/:league/:year', async (req, res) => {
-  const league = req.params.league;
-  const year = req.params.year;
-  const query = league + year;
-  try {
-    client.get(query, async (err, leagueTable) => {
-      if (err) throw err;
+app.get('/v2/:league/:year', 
+  [
+    // League id must be one of these
+    param('league').isIn(['39', '40', '41', '42']),
+    // Year must be no earlier than 2018
+    param('year').isIn(['2018', '2019', '2020', '2021']),
+  ],
+  async (req, res) => {
+    // Validate
+    const errors = validationResult(req);
+    if (!errors.isEmpty()) {
+      return res.status(422).json({ errors: errors.array() });
+    }
+    // Begin method
+    const league = req.params.league;
+    const year = req.params.year;
+    const query = league + year;
+    try {
+      client.get(query, async (err, leagueTable) => {
+        if (err) throw err;
 
-      // Return cached league table if present
-      if (leagueTable) {
-        res.status(200).send({
-          table: JSON.parse(leagueTable),
-          message: 'data retrieved from cache',
-        });
-      } else {
-        // Fetch from the API
-        reqSeason = new LeagueSeason(league, year);
-        const leagueTable = await axios.get(
-          'https://v3.football.api-sports.io/standings',
-          reqSeason
-        );
-        // Save result to cache
-        client.setex(query, 43200, JSON.stringify(leagueTable.data));
-        // Return data from API
-        res.status(200).send({
-          table: leagueTable.data,
-          message: 'cache miss',
-        });
-      }
-    });
-  } catch (err) {
-    res.status(500).send({ message: err.message });
-  }
+        // Return cached league table if present
+        if (leagueTable) {
+          res.status(200).send({
+            table: JSON.parse(leagueTable),
+            message: 'data retrieved from cache',
+          });
+        } else {
+          // Fetch from the API
+          reqSeason = new LeagueSeason(league, year);
+          const leagueTable = await axios.get(
+            'https://v3.football.api-sports.io/standings',
+            reqSeason
+          );
+          // Save result to cache
+          client.setex(query, 43200, JSON.stringify(leagueTable.data));
+          // Return data from API
+          res.status(200).send({
+            table: leagueTable.data,
+            message: 'cache miss',
+          });
+        }
+      });
+    } catch (err) {
+      res.status(500).send({ message: err.message });
+    }
 });
 
 app.listen(process.env.PORT || 3001, () => {
diff --git a/package-lock.json b/package-lock.json
index 9079750..6b1bfd1 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -12,11 +12,15 @@
         "axios": "^0.21.1",
         "cors": "^2.8.5",
         "express": "^4.17.1",
+        "express-validator": "^6.12.1",
         "redis": "^3.1.2"
       },
       "devDependencies": {
         "dotenv": "^10.0.0",
         "nodemon": "^2.0.12"
+      },
+      "engines": {
+        "node": "14.x"
       }
     },
     "node_modules/@sindresorhus/is": {
@@ -668,6 +672,18 @@
         "node": ">= 0.10.0"
       }
     },
+    "node_modules/express-validator": {
+      "version": "6.12.1",
+      "resolved": "https://registry.npmjs.org/express-validator/-/express-validator-6.12.1.tgz",
+      "integrity": "sha512-olpTAv0ZB5IhNuDQ2rodKAuJsewgFgLIsczJMAWD6T0Yvxsa+j/Hk61jl8e26lAq+oJr6hUqPRjdlOBKhFlWeQ==",
+      "dependencies": {
+        "lodash": "^4.17.21",
+        "validator": "^13.5.2"
+      },
+      "engines": {
+        "node": ">= 8.0.0"
+      }
+    },
     "node_modules/express/node_modules/debug": {
       "version": "2.6.9",
       "resolved": "https://registry.npmjs.org/debug/-/debug-2.6.9.tgz",
@@ -1077,6 +1093,11 @@
         "node": ">=8"
       }
     },
+    "node_modules/lodash": {
+      "version": "4.17.21",
+      "resolved": "https://registry.npmjs.org/lodash/-/lodash-4.17.21.tgz",
+      "integrity": "sha512-v2kDEe57lecTulaDIuNTPy3Ry4gLGJ6Z1O3vE1krgXZNrsQ+LFTGHVxVjcXPs17LhbZVGedAJv8XZ1tvj5FvSg=="
+    },
     "node_modules/lowercase-keys": {
       "version": "1.0.1",
       "resolved": "https://registry.npmjs.org/lowercase-keys/-/lowercase-keys-1.0.1.tgz",
@@ -1866,6 +1887,14 @@
         "node": ">= 0.4.0"
       }
     },
+    "node_modules/validator": {
+      "version": "13.6.0",
+      "resolved": "https://registry.npmjs.org/validator/-/validator-13.6.0.tgz",
+      "integrity": "sha512-gVgKbdbHgtxpRyR8K0O6oFZPhhB5tT1jeEHZR0Znr9Svg03U0+r9DXWMrnRAB+HtCStDQKlaIZm42tVsVjqtjg==",
+      "engines": {
+        "node": ">= 0.10"
+      }
+    },
     "node_modules/vary": {
       "version": "1.1.2",
       "resolved": "https://registry.npmjs.org/vary/-/vary-1.1.2.tgz",
@@ -2450,6 +2479,15 @@
         }
       }
     },
+    "express-validator": {
+      "version": "6.12.1",
+      "resolved": "https://registry.npmjs.org/express-validator/-/express-validator-6.12.1.tgz",
+      "integrity": "sha512-olpTAv0ZB5IhNuDQ2rodKAuJsewgFgLIsczJMAWD6T0Yvxsa+j/Hk61jl8e26lAq+oJr6hUqPRjdlOBKhFlWeQ==",
+      "requires": {
+        "lodash": "^4.17.21",
+        "validator": "^13.5.2"
+      }
+    },
     "fill-range": {
       "version": "7.0.1",
       "resolved": "https://registry.npmjs.org/fill-range/-/fill-range-7.0.1.tgz",
@@ -2743,6 +2781,11 @@
         "package-json": "^6.3.0"
       }
     },
+    "lodash": {
+      "version": "4.17.21",
+      "resolved": "https://registry.npmjs.org/lodash/-/lodash-4.17.21.tgz",
+      "integrity": "sha512-v2kDEe57lecTulaDIuNTPy3Ry4gLGJ6Z1O3vE1krgXZNrsQ+LFTGHVxVjcXPs17LhbZVGedAJv8XZ1tvj5FvSg=="
+    },
     "lowercase-keys": {
       "version": "1.0.1",
       "resolved": "https://registry.npmjs.org/lowercase-keys/-/lowercase-keys-1.0.1.tgz",
@@ -3343,6 +3386,11 @@
       "resolved": "https://registry.npmjs.org/utils-merge/-/utils-merge-1.0.1.tgz",
       "integrity": "sha1-n5VxD1CiZ5R7LMwSR0HBAoQn5xM="
     },
+    "validator": {
+      "version": "13.6.0",
+      "resolved": "https://registry.npmjs.org/validator/-/validator-13.6.0.tgz",
+      "integrity": "sha512-gVgKbdbHgtxpRyR8K0O6oFZPhhB5tT1jeEHZR0Znr9Svg03U0+r9DXWMrnRAB+HtCStDQKlaIZm42tVsVjqtjg=="
+    },
     "vary": {
       "version": "1.1.2",
       "resolved": "https://registry.npmjs.org/vary/-/vary-1.1.2.tgz",
diff --git a/package.json b/package.json
index afe7e58..f80c6cf 100644
--- a/package.json
+++ b/package.json
@@ -20,6 +20,7 @@
     "axios": "^0.21.1",
     "cors": "^2.8.5",
     "express": "^4.17.1",
+    "express-validator": "^6.12.1",
     "redis": "^3.1.2"
   }
 }