diff --git a/index.js b/index.js
index c0638e08..5739707f 100644
--- a/index.js
+++ b/index.js
@@ -40,7 +40,7 @@ var hasBrotliSupport = 'createBrotliCompress' in zlib
  * Module variables.
  * @private
  */
-var cacheControlNoTransformRegExp = /(?:^|,)\s*?no-transform\s*?(?:,|$)/
+var cacheControlNoTransformRegExp = /(?:^|,)\s*?no-transform\s*?(?:,|$)/i
 var SUPPORTED_ENCODING = hasBrotliSupport ? ['br', 'gzip', 'deflate', 'identity'] : ['gzip', 'deflate', 'identity']
 var PREFERRED_ENCODING = hasBrotliSupport ? ['br', 'gzip'] : ['gzip']
 
diff --git a/test/compression.js b/test/compression.js
index 8107def0..df37eca2 100644
--- a/test/compression.js
+++ b/test/compression.js
@@ -706,6 +706,21 @@ describe('compression()', function () {
         .expect(200, 'hello, world', done)
     })
 
+    it('should match directive case-insensitively', function (done) {
+      var server = createServer({ threshold: 0 }, function (req, res) {
+        res.setHeader('Cache-Control', 'No-Transform')
+        res.setHeader('Content-Type', 'text/plain')
+        res.end('hello, world')
+      })
+
+      request(server)
+        .get('/')
+        .set('Accept-Encoding', 'gzip')
+        .expect('Cache-Control', 'No-Transform')
+        .expect(shouldNotHaveHeader('Content-Encoding'))
+        .expect(200, 'hello, world', done)
+    })
+
     it('should not set Vary headerh', function (done) {
       var server = createServer({ threshold: 0 }, function (req, res) {
         res.setHeader('Cache-Control', 'no-transform')