diff --git a/examples/lookup.js b/examples/lookup.js
index 1289fe4..b97fb4e 100755
--- a/examples/lookup.js
+++ b/examples/lookup.js
@@ -4,6 +4,7 @@ const wordnet = require('../lib/wordnet.js');
 program
   .version('0.0.1')
   .usage('<word>')
+  .option('-d, --database <database-path>', 'Location of WordNet index and data files.')
   .parse(process.argv);
 
 /* Word to look up */
diff --git a/lib/wordnet.js b/lib/wordnet.js
index a2f05e9..66ce5a5 100644
--- a/lib/wordnet.js
+++ b/lib/wordnet.js
@@ -34,18 +34,26 @@ function getKey(word) { return `${KEY_PREFIX}${word}` }
  *
  * @return {Promise} Empty promise object.
  */
-module.exports.init = async function() {
+module.exports.init = async function(databaseDir) {
   const extensions = Object.keys(EXTENSIONS_MAP);
 
+  if (!databaseDir) {
+    databaseDir = __dirname + '/../db';
+  }
+
   // Read data from all index files into memory.
   // NOTE: We have to run this serially in order to ensure consistent results.
   await extensions.reduce((p, ext) => {
-    return p.then(() => readIndex(ext));
+    return p.then(() => {
+      return readIndex(`${databaseDir}/index.${ext}`);
+    });
   }, Promise.resolve());
 
   // Load the contents from the data files into memory.
   await Promise.all(extensions.map((ext) => {
-    return readDatabase(ext).then((fileHandle) => _data[EXTENSIONS_MAP[ext]] = fileHandle);
+    return readDatabase(`${databaseDir}/data.${ext}`).then((fileHandle) => {
+      _data[EXTENSIONS_MAP[ext]] = fileHandle;
+    });
   }));
 
   return Promise.resolve();
@@ -107,9 +115,9 @@ function readData(definition, skipPointers) {
   });
 }
 
-function readIndex(extension) {
+function readIndex(filePath) {
   return new Promise((resolve) => {
-    reader.read(__dirname + '/../db/index.' + extension, (line) => {
+    reader.read(filePath, (line) => {
       let result = parseIndexLine(line);
 
       if (!result.isComment) {
@@ -130,8 +138,8 @@ function readIndex(extension) {
  * @param {String} extension WordNet DB extension.
  * @return {Promise} Resolves with FileHandle object.
  */
-function readDatabase(extension) {
-  return fsp.open(__dirname + '/../db/data.' + extension, 'r');
+function readDatabase(filePath) {
+  return fsp.open(filePath, 'r');
 }
 
 /**
diff --git a/test/wordnet.js b/test/wordnet.js
index 87810f8..86b4ad8 100644
--- a/test/wordnet.js
+++ b/test/wordnet.js
@@ -11,6 +11,7 @@ test('api', async (t) => {
   // - Calling API functions before init.
   // - Searching for a word not in the database.
 
+  // TODO: Add test for initializing with a custom path.
   await wordnet.init();
 
   let list = await wordnet.list();