diff --git a/HISTORY.md b/HISTORY.md
index 3846cf0..167fafb 100644
--- a/HISTORY.md
+++ b/HISTORY.md
@@ -1,3 +1,8 @@
+unreleased
+==========
+
+  * Slightly improve speed for weak ETags over 1KB
+
 1.4.0 / 2014-09-21
 ==================
 
diff --git a/README.md b/README.md
index d770f49..16aaa20 100644
--- a/README.md
+++ b/README.md
@@ -51,7 +51,7 @@ $ npm test
 ```bash
 $ npm run-script bench
 
-> etag@1.2.0 bench nodejs-etag
+> etag@1.5.0-pre bench nodejs-etag
 > node benchmark/index.js
 
 > node benchmark/body0-100b.js
@@ -63,10 +63,10 @@ $ npm run-script bench
   3 tests completed.
   4 tests completed.
 
-  buffer - strong x   518,895 ops/sec ±1.71% (185 runs sampled)
-* buffer - weak   x 1,917,975 ops/sec ±0.34% (195 runs sampled)
-  string - strong x   245,251 ops/sec ±0.90% (190 runs sampled)
-  string - weak   x   442,232 ops/sec ±0.21% (196 runs sampled)
+  buffer - strong x   426,717 ops/sec ±1.34% (181 runs sampled)
+* buffer - weak   x 1,081,596 ops/sec ±0.32% (196 runs sampled)
+  string - strong x   235,880 ops/sec ±1.01% (190 runs sampled)
+  string - weak   x   373,234 ops/sec ±0.87% (192 runs sampled)
 
 > node benchmark/body1-1kb.js
 
@@ -77,10 +77,10 @@ $ npm run-script bench
   3 tests completed.
   4 tests completed.
 
-  buffer - strong x 309,748 ops/sec ±0.99% (191 runs sampled)
-* buffer - weak   x 352,402 ops/sec ±0.20% (198 runs sampled)
-  string - strong x 159,058 ops/sec ±1.83% (191 runs sampled)
-  string - weak   x 184,052 ops/sec ±1.30% (189 runs sampled)
+  buffer - strong x 274,188 ops/sec ±1.17% (192 runs sampled)
+* buffer - weak   x 298,451 ops/sec ±0.49% (194 runs sampled)
+  string - strong x 157,331 ops/sec ±2.12% (186 runs sampled)
+  string - weak   x 169,242 ops/sec ±1.51% (188 runs sampled)
 
 > node benchmark/body2-5kb.js
 
@@ -91,10 +91,10 @@ $ npm run-script bench
   3 tests completed.
   4 tests completed.
 
-* buffer - strong x 110,157 ops/sec ±0.60% (194 runs sampled)
-* buffer - weak   x 111,333 ops/sec ±0.67% (194 runs sampled)
-  string - strong x  62,091 ops/sec ±3.92% (186 runs sampled)
-  string - weak   x  60,681 ops/sec ±3.98% (186 runs sampled)
+  buffer - strong x 102,624 ops/sec ±0.93% (193 runs sampled)
+* buffer - weak   x 104,696 ops/sec ±1.17% (190 runs sampled)
+  string - strong x  59,097 ops/sec ±3.93% (186 runs sampled)
+  string - weak   x  59,202 ops/sec ±4.01% (185 runs sampled)
 
 > node benchmark/body3-10kb.js
 
@@ -105,10 +105,10 @@ $ npm run-script bench
   3 tests completed.
   4 tests completed.
 
-* buffer - strong x 61,843 ops/sec ±0.44% (197 runs sampled)
-* buffer - weak   x 61,687 ops/sec ±0.52% (197 runs sampled)
-  string - strong x 41,377 ops/sec ±3.33% (189 runs sampled)
-  string - weak   x 41,368 ops/sec ±3.29% (190 runs sampled)
+  buffer - strong x 54,768 ops/sec ±1.43% (188 runs sampled)
+* buffer - weak   x 57,393 ops/sec ±1.10% (192 runs sampled)
+  string - strong x 36,597 ops/sec ±3.81% (179 runs sampled)
+  string - weak   x 35,525 ops/sec ±3.82% (186 runs sampled)
 
 > node benchmark/body4-100kb.js
 
@@ -119,10 +119,10 @@ $ npm run-script bench
   3 tests completed.
   4 tests completed.
 
-* buffer - strong x 6,874 ops/sec ±0.17% (198 runs sampled)
-* buffer - weak   x 6,880 ops/sec ±0.15% (198 runs sampled)
-  string - strong x 5,382 ops/sec ±2.17% (192 runs sampled)
-  string - weak   x 5,361 ops/sec ±2.23% (192 runs sampled)
+* buffer - strong x 6,243 ops/sec ±0.84% (194 runs sampled)
+* buffer - weak   x 6,312 ops/sec ±0.95% (193 runs sampled)
+  string - strong x 4,984 ops/sec ±2.21% (191 runs sampled)
+  string - weak   x 5,068 ops/sec ±2.32% (190 runs sampled)
 ```
 
 ## License
diff --git a/index.js b/index.js
index 3366af8..ce9787a 100644
--- a/index.js
+++ b/index.js
@@ -59,7 +59,7 @@ function etag(entity, options) {
   var buf = !isBuffer
     ? new Buffer(entity, 'utf8')
     : entity
-  var hash = weak && buf.length <= crc32threshold
+  var hash = weak
     ? weakhash(buf)
     : stronghash(buf)
 
@@ -157,5 +157,14 @@ function weakhash(buf) {
     return '0-0'
   }
 
-  return buf.length.toString(16) + '-' + crc(buf).toString(16)
+  if (buf.length <= crc32threshold) {
+    // crc32 plus length when it's fast
+    return buf.length.toString(16) + '-' + crc(buf).toString(16)
+  }
+
+  // use md4 for long strings
+  return crypto
+    .createHash('md4')
+    .update(buf)
+    .digest('base64')
 }
diff --git a/test/test.js b/test/test.js
index f7e8121..0708117 100644
--- a/test/test.js
+++ b/test/test.js
@@ -86,13 +86,13 @@ describe('etag(entity)', function () {
       it('should generate a weak ETag for a string', function () {
         assert.equal(etag('', {weak: true}), 'W/"0-0"')
         assert.equal(etag('beep boop', {weak: true}), 'W/"9-7f3ee715"')
-        assert.equal(etag(str5kb, {weak: true}), 'W/"8Kq68cJq4i+5US7RLWrE1g=="')
+        assert.equal(etag(str5kb, {weak: true}), 'W/"3Ikd9BFqLeTIltAti5IvKg=="')
       })
 
       it('should generate a weak ETag for a Buffer', function () {
         assert.equal(etag(new Buffer(0), {weak: true}), 'W/"0-0"')
         assert.equal(etag(new Buffer([1, 2, 3]), {weak: true}), 'W/"3-55bc801d"')
-        assert.equal(etag(buf5kb, {weak: true}), 'W/"8Kq68cJq4i+5US7RLWrE1g=="')
+        assert.equal(etag(buf5kb, {weak: true}), 'W/"3Ikd9BFqLeTIltAti5IvKg=="')
       })
 
       it('should generate a weak ETag for fs.Stats', function () {