diff --git a/package-lock.json b/package-lock.json
index de717340..9571087c 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -3289,7 +3289,8 @@
       "version": "1.3.0",
       "resolved": "https://registry.npmjs.org/growly/-/growly-1.3.0.tgz",
       "integrity": "sha1-8QdIy+dq+WS3yWyTxrzCivEgwIE=",
-      "dev": true
+      "dev": true,
+      "optional": true
     },
     "handlebars": {
       "version": "4.7.7",
@@ -3760,6 +3761,7 @@
       "resolved": "https://registry.npmjs.org/is-wsl/-/is-wsl-2.2.0.tgz",
       "integrity": "sha512-fKzAra0rGJUUBwGBgNkHZuToZcn+TtXHpeCgmkMJMMYx1sQDYaCSyjJBSCa2nH1DGm7s3n1oBnohoVTBaN7Lww==",
       "dev": true,
+      "optional": true,
       "requires": {
         "is-docker": "^2.0.0"
       }
@@ -5711,9 +5713,9 @@
       }
     },
     "mmdb-lib": {
-      "version": "1.2.0",
-      "resolved": "https://registry.npmjs.org/mmdb-lib/-/mmdb-lib-1.2.0.tgz",
-      "integrity": "sha512-3XYebkStxqCgWJjsmT9FCaE19Yi4Tvs2SBPKhUks3rJJh52oF1AKAd9kei+LTutud3a6RCZ0o2Um96Fn7o3zVA=="
+      "version": "1.3.0",
+      "resolved": "https://registry.npmjs.org/mmdb-lib/-/mmdb-lib-1.3.0.tgz",
+      "integrity": "sha512-KrRrAuC+X9ZkkPZNsqgHUGrop28vcmqISILyUXG0xOYt82ObU9d9XowVsjOVOr5CegyjrkmxEN5ut9r576vq2g=="
     },
     "modify-values": {
       "version": "1.0.1",
@@ -5826,6 +5828,7 @@
       "resolved": "https://registry.npmjs.org/node-notifier/-/node-notifier-8.0.1.tgz",
       "integrity": "sha512-BvEXF+UmsnAfYfoapKM9nGxnP+Wn7P91YfXmrKnfcYCx6VBeoN5Ez5Ogck6I8Bi5k4RlpqRYaw75pAwzX9OphA==",
       "dev": true,
+      "optional": true,
       "requires": {
         "growly": "^1.3.0",
         "is-wsl": "^2.2.0",
@@ -5840,6 +5843,7 @@
           "resolved": "https://registry.npmjs.org/semver/-/semver-7.3.4.tgz",
           "integrity": "sha512-tCfb2WLjqFAtXn4KEdxIhalnRtoKFN7nAwj0B3ZXCbQloV2tq5eDbcTmT68JJD3nRJq24/XgxtQKFIpQdtvmVw==",
           "dev": true,
+          "optional": true,
           "requires": {
             "lru-cache": "^6.0.0"
           }
@@ -5849,6 +5853,7 @@
           "resolved": "https://registry.npmjs.org/which/-/which-2.0.2.tgz",
           "integrity": "sha512-BLI3Tl1TW3Pvl70l3yq3Y64i+awpwXqsGBYWkkqMtnbXgrMD+yj7rhW0kuEDxzJaYXGjEW5ogapKNMEKNMjibA==",
           "dev": true,
+          "optional": true,
           "requires": {
             "isexe": "^2.0.0"
           }
@@ -9220,7 +9225,8 @@
       "version": "0.1.1",
       "resolved": "https://registry.npmjs.org/shellwords/-/shellwords-0.1.1.tgz",
       "integrity": "sha512-vFwSUfQvqybiICwZY5+DAWIPLKsWO31Q91JSKl3UYv+K5c2QRPzn0qzec6QPu1Qc9eHYItiP3NdJqNVqetYAww==",
-      "dev": true
+      "dev": true,
+      "optional": true
     },
     "signal-exit": {
       "version": "3.0.2",
@@ -10299,7 +10305,8 @@
       "version": "8.3.1",
       "resolved": "https://registry.npmjs.org/uuid/-/uuid-8.3.1.tgz",
       "integrity": "sha512-FOmRr+FmWEIG8uhZv6C2bTgEVXsHk08kE7mPlrBbEe+c3r9pjceVPgupIfNIhc4yx55H69OXANrUaSuu9eInKg==",
-      "dev": true
+      "dev": true,
+      "optional": true
     },
     "v8-to-istanbul": {
       "version": "7.0.0",
diff --git a/package.json b/package.json
index cf13aa5c..4e911cb5 100644
--- a/package.json
+++ b/package.json
@@ -26,7 +26,7 @@
     "Gregory Oschwald @oschwald"
   ],
   "dependencies": {
-    "mmdb-lib": "1.2.0",
+    "mmdb-lib": "1.3.0",
     "tiny-lru": "7.0.6"
   },
   "devDependencies": {
diff --git a/src/index.ts b/src/index.ts
index 3e2e70cd..3d9d4302 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -33,7 +33,7 @@ export const open = async <T>(
   }
 
   const cache = lru((opts && opts.cache && opts.cache.max) || 6000);
-  let reader = new Reader<T>(database, { cache });
+  const reader = new Reader<T>(database, { cache });
 
   if (opts && !!opts.watchForUpdates) {
     if (
@@ -63,9 +63,9 @@ export const open = async <T>(
       if (!(await waitExists())) {
         return;
       }
-      const updateDatabase = await fs.readFile(filepath);
+      const updatedDatabase = await fs.readFile(filepath);
       cache.clear();
-      reader = new Reader<T>(updateDatabase, { cache });
+      reader.load(updatedDatabase);
       if (opts.watchForUpdatesHook) {
         opts.watchForUpdatesHook();
       }
@@ -94,4 +94,4 @@ export default {
   validate: ip.validate,
 };
 
-export { Reader };
\ No newline at end of file
+export { Reader };
diff --git a/test/README.md b/test/README.md
new file mode 100644
index 00000000..db1ad1f2
--- /dev/null
+++ b/test/README.md
@@ -0,0 +1,7 @@
+# Test data
+
+Test data is installed via _git submodule_ from https://github.com/maxmind/MaxMind-DB.git. Execute following command in the project root:
+
+```shell
+git submodule update --init
+```