diff --git a/src/core/stream.js b/src/core/stream.js
index 2b818b9fb..2b81c6aeb 100644
--- a/src/core/stream.js
+++ b/src/core/stream.js
@@ -292,25 +292,25 @@ var StreamsSequenceStream = (function StreamsSequenceStreamClosure() {
 })();
 
 var FlateStream = (function FlateStreamClosure() {
-  var codeLenCodeMap = new Uint32Array([
+  var codeLenCodeMap = new Int32Array([
     16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15
   ]);
 
-  var lengthDecode = new Uint32Array([
+  var lengthDecode = new Int32Array([
     0x00003, 0x00004, 0x00005, 0x00006, 0x00007, 0x00008, 0x00009, 0x0000a,
     0x1000b, 0x1000d, 0x1000f, 0x10011, 0x20013, 0x20017, 0x2001b, 0x2001f,
     0x30023, 0x3002b, 0x30033, 0x3003b, 0x40043, 0x40053, 0x40063, 0x40073,
     0x50083, 0x500a3, 0x500c3, 0x500e3, 0x00102, 0x00102, 0x00102
   ]);
 
-  var distDecode = new Uint32Array([
+  var distDecode = new Int32Array([
     0x00001, 0x00002, 0x00003, 0x00004, 0x10005, 0x10007, 0x20009, 0x2000d,
     0x30011, 0x30019, 0x40021, 0x40031, 0x50041, 0x50061, 0x60081, 0x600c1,
     0x70101, 0x70181, 0x80201, 0x80301, 0x90401, 0x90601, 0xa0801, 0xa0c01,
     0xb1001, 0xb1801, 0xc2001, 0xc3001, 0xd4001, 0xd6001
   ]);
 
-  var fixedLitCodeTab = [new Uint32Array([
+  var fixedLitCodeTab = [new Int32Array([
     0x70100, 0x80050, 0x80010, 0x80118, 0x70110, 0x80070, 0x80030, 0x900c0,
     0x70108, 0x80060, 0x80020, 0x900a0, 0x80000, 0x80080, 0x80040, 0x900e0,
     0x70104, 0x80058, 0x80018, 0x90090, 0x70114, 0x80078, 0x80038, 0x900d0,
@@ -377,7 +377,7 @@ var FlateStream = (function FlateStreamClosure() {
     0x7010f, 0x8006f, 0x8002f, 0x900bf, 0x8000f, 0x8008f, 0x8004f, 0x900ff
   ]), 9];
 
-  var fixedDistCodeTab = [new Uint32Array([
+  var fixedDistCodeTab = [new Int32Array([
     0x50000, 0x50010, 0x50008, 0x50018, 0x50004, 0x50014, 0x5000c, 0x5001c,
     0x50002, 0x50012, 0x5000a, 0x5001a, 0x50006, 0x50016, 0x5000e, 0x00000,
     0x50001, 0x50011, 0x50009, 0x50019, 0x50005, 0x50015, 0x5000d, 0x5001d,
@@ -474,7 +474,7 @@ var FlateStream = (function FlateStreamClosure() {
 
     // build the table
     var size = 1 << maxLen;
-    var codes = new Uint32Array(size);
+    var codes = new Int32Array(size);
     for (var len = 1, code = 0, skip = 2;
          len <= maxLen;
          ++len, code <<= 1, skip <<= 1) {