diff --git a/index.js b/index.js
index e6e0d6e..7553089 100644
--- a/index.js
+++ b/index.js
@@ -5,7 +5,7 @@ const supportsColor = require('supports-color');
 
 const template = require('./templates.js');
 
-const isSimpleWindowsTerm = process.platform === 'win32' && !process.env.TERM.toLowerCase().startsWith('xterm');
+const isSimpleWindowsTerm = process.platform === 'win32' && !(process.env.TERM || '').toLowerCase().startsWith('xterm');
 
 // `supportsColor.level` → `ansiStyles.color[name]` mapping
 const levelMapping = ['ansi', 'ansi', 'ansi256', 'ansi16m'];
diff --git a/test.js b/test.js
index a7a4a6b..237e3f3 100644
--- a/test.js
+++ b/test.js
@@ -133,6 +133,12 @@ describe('chalk on windows', () => {
 		delete require.cache[resolveFrom(__dirname, 'ansi-styles')];
 	});
 
+	it('should detect a simple term if TERM isn\'t set', () => {
+		delete process.env.TERM;
+		const chalkCtx = importFresh('.');
+		assert.equal(chalkCtx.blue('foo'), '\u001B[94mfoo\u001B[39m');
+	});
+
 	it('should replace blue foreground color in cmd.exe', () => {
 		process.env.TERM = 'dumb';
 		const chalkCtx = importFresh('.');