diff --git a/bower.json b/bower.json
index 2d5d339..a995f68 100644
--- a/bower.json
+++ b/bower.json
@@ -1,6 +1,6 @@
 {
   "name": "crypto-js",
-  "version": "3.1.8",
+  "version": "3.1.9",
   "description": "JavaScript library of crypto standards.",
   "license": "MIT",
   "homepage": "http://github.com/brix/crypto-js",
diff --git a/cipher-core.js b/cipher-core.js
index 4fad569..751c816 100644
--- a/cipher-core.js
+++ b/cipher-core.js
@@ -1,11 +1,11 @@
-;(function (root, factory) {
+;(function (root, factory, undef) {
 	if (typeof exports === "object") {
 		// CommonJS
-		module.exports = exports = factory(require("./core"));
+		module.exports = exports = factory(require("./core"), require("./evpkdf"));
 	}
 	else if (typeof define === "function" && define.amd) {
 		// AMD
-		define(["./core"], factory);
+		define(["./core", "./evpkdf"], factory);
 	}
 	else {
 		// Global (browser)
@@ -466,11 +466,16 @@
 	                var modeCreator = mode.createEncryptor;
 	            } else /* if (this._xformMode == this._DEC_XFORM_MODE) */ {
 	                var modeCreator = mode.createDecryptor;
-
 	                // Keep at least one block in the buffer for unpadding
 	                this._minBufferSize = 1;
 	            }
-	            this._mode = modeCreator.call(mode, this, iv && iv.words);
+
+	            if (this._mode && this._mode.__creator == modeCreator) {
+	                this._mode.init(this, iv && iv.words);
+	            } else {
+	                this._mode = modeCreator.call(mode, this, iv && iv.words);
+	                this._mode.__creator = modeCreator;
+	            }
 	        },
 
 	        _doProcessBlock: function (words, offset) {
diff --git a/crypto-js.js b/crypto-js.js
index 3b6c221..17f2b11 100644
--- a/crypto-js.js
+++ b/crypto-js.js
@@ -3717,11 +3717,16 @@
 	                var modeCreator = mode.createEncryptor;
 	            } else /* if (this._xformMode == this._DEC_XFORM_MODE) */ {
 	                var modeCreator = mode.createDecryptor;
-
 	                // Keep at least one block in the buffer for unpadding
 	                this._minBufferSize = 1;
 	            }
-	            this._mode = modeCreator.call(mode, this, iv && iv.words);
+
+	            if (this._mode && this._mode.__creator == modeCreator) {
+	                this._mode.init(this, iv && iv.words);
+	            } else {
+	                this._mode = modeCreator.call(mode, this, iv && iv.words);
+	                this._mode.__creator = modeCreator;
+	            }
 	        },
 
 	        _doProcessBlock: function (words, offset) {
diff --git a/package.json b/package.json
index 50f9de9..dae37ed 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "crypto-js",
-  "version": "3.1.8",
+  "version": "3.1.9",
   "description": "JavaScript library of crypto standards.",
   "license": "MIT",
   "author": {