diff --git a/lib/packer.js b/lib/packer.js
index d069448..19046c8 100755
--- a/lib/packer.js
+++ b/lib/packer.js
@@ -35,8 +35,8 @@ var Packer = module.exports = function(options) {
     this._options = options;
 
     options.deflateChunkSize = options.deflateChunkSize || 32 * 1024;
-    options.deflateLevel = options.deflateLevel || 9;
-    options.deflateStrategy = options.deflateStrategy || 3;
+    options.deflateLevel = options.deflateLevel != null ? options.deflateLevel : 9;
+    options.deflateStrategy = options.deflateStrategy != null ? options.deflateStrategy : 3;
 
     this.readable = true;
 };