diff --git a/emsdk/emscripten/tag-1.38.31/src/library_lz4.js b/emsdk/emscripten/tag-1.38.31/src/library_lz4.js
index 4c3f583b7..5291002a4 100644
--- a/emsdk/emscripten/tag-1.38.31/src/library_lz4.js
+++ b/emsdk/emscripten/tag-1.38.31/src/library_lz4.js
@@ -5,26 +5,14 @@ mergeInto(LibraryManager.library, {
     DIR_MODE: {{{ cDefine('S_IFDIR') }}} | 511 /* 0777 */,
     FILE_MODE: {{{ cDefine('S_IFREG') }}} | 511 /* 0777 */,
     CHUNK_SIZE: -1,
-    codec: null,
     init: function() {
-      if (LZ4.codec) return;
-      LZ4.codec = (function() {
-        {{{ read('mini-lz4.js') }}};
-        return MiniLZ4;
-      })();
-      LZ4.CHUNK_SIZE = LZ4.codec.CHUNK_SIZE;
+      LZ4.CHUNK_SIZE = 2048;
     },
     loadPackage: function (pack) {
       LZ4.init();
       var compressedData = pack['compressedData'];
-      if (!compressedData) compressedData = LZ4.codec.compressPackage(pack['data']);
+      // if (!compressedData) compressedData = LZ4.codec.compressPackage(pack['data']);
       assert(compressedData.cachedIndexes.length === compressedData.cachedChunks.length);
-      for (var i = 0; i < compressedData.cachedIndexes.length; i++) {
-        compressedData.cachedIndexes[i] = -1;
-        compressedData.cachedChunks[i] = compressedData.data.subarray(compressedData.cachedOffset + i*LZ4.CHUNK_SIZE,
-                                                                      compressedData.cachedOffset + (i+1)*LZ4.CHUNK_SIZE);
-        assert(compressedData.cachedChunks[i].length === LZ4.CHUNK_SIZE);
-      }
       pack['metadata'].files.forEach(function(file) {
         var dir = PATH.dirname(file.filename);
         var name = PATH.basename(file.filename);
@@ -36,6 +24,12 @@ mergeInto(LibraryManager.library, {
           end: file.end,
         });
       });
+      compressedData.buf = Module['_malloc'](LZ4.CHUNK_SIZE);
+      for (var i = 0; i < compressedData.cachedIndexes.length; i++) {
+        compressedData.cachedIndexes[i] = -1;
+        compressedData.cachedChunks[i] = Module['_malloc'](LZ4.CHUNK_SIZE);
+        assert(compressedData.cachedChunks[i] !== null)
+      }
     },
     createNode: function (parent, name, mode, dev, contents, mtime) {
       var node = FS.createNode(parent, name, mode);
@@ -112,6 +106,7 @@ mergeInto(LibraryManager.library, {
         //console.log('LZ4 read ' + [offset, length, position]);
         length = Math.min(length, stream.node.size - position);
         if (length <= 0) return 0;
+
         var contents = stream.node.contents;
         var compressedData = contents.compressedData;
         var written = 0;
@@ -122,11 +117,14 @@ mergeInto(LibraryManager.library, {
           var chunkIndex = Math.floor(start / LZ4.CHUNK_SIZE);
           var compressedStart = compressedData.offsets[chunkIndex];
           var compressedSize = compressedData.sizes[chunkIndex];
+          var startInChunk = start % LZ4.CHUNK_SIZE;
+          var endInChunk = Math.min(startInChunk + desired, LZ4.CHUNK_SIZE);
           var currChunk;
           if (compressedData.successes[chunkIndex]) {
             var found = compressedData.cachedIndexes.indexOf(chunkIndex);
             if (found >= 0) {
               currChunk = compressedData.cachedChunks[found];
+              buffer.set(Module.HEAPU8.subarray(currChunk + startInChunk, currChunk + endInChunk), offset + written);
             } else {
               // decompress the chunk
               compressedData.cachedIndexes.pop();
@@ -138,18 +136,19 @@ mergeInto(LibraryManager.library, {
                 Module['decompressedChunks'] = (Module['decompressedChunks'] || 0) + 1;
               }
               var compressed = compressedData.data.subarray(compressedStart, compressedStart + compressedSize);
-              //var t = Date.now();
-              var originalSize = LZ4.codec.uncompress(compressed, currChunk);
-              //console.log('decompress time: ' + (Date.now() - t));
+              // var t = Date.now();
+              // var originalSize = LZ4.codec.uncompress(compressed, currChunk);
+              Module.HEAPU8.set(compressed, compressedData.buf);
+              var originalSize = Module['_LZ4_decompress_safe'](compressedData.buf, currChunk, compressedSize, LZ4.CHUNK_SIZE);
+              // console.log('decompress time: ' + (Date.now() - t));
               if (chunkIndex < compressedData.successes.length-1) assert(originalSize === LZ4.CHUNK_SIZE); // all but the last chunk must be full-size
+              buffer.set(Module.HEAPU8.subarray(currChunk + startInChunk, currChunk + endInChunk), offset + written);
             }
-          } else {
+          }
+          else {
             // uncompressed
-            currChunk = compressedData.data.subarray(compressedStart, compressedStart + LZ4.CHUNK_SIZE);
+            buffer.set(compressedData.data.subarray(compressedStart + startInChunk, compressedStart + endInChunk), offset + written);
           }
-          var startInChunk = start % LZ4.CHUNK_SIZE;
-          var endInChunk = Math.min(startInChunk + desired, LZ4.CHUNK_SIZE);
-          buffer.set(currChunk.subarray(startInChunk, endInChunk), offset + written);
           var currWritten = endInChunk - startInChunk;
           written += currWritten;
         }
@@ -181,4 +180,3 @@ if (LibraryManager.library['$FS__deps']) {
   warn('FS does not seem to be in use (no preloaded files etc.), LZ4 will not do anything');
 }
 #endif
-