diff --git a/lib/security/jsbn.js b/lib/security/jsbn.js
index 28ca2f2..209c127 100644
--- a/lib/security/jsbn.js
+++ b/lib/security/jsbn.js
@@ -1,6 +1,6 @@
 /*
  * Basic JavaScript BN library - subset useful for RSA encryption.
- * 
+ *
  * Copyright (c) 2003-2005  Tom Wu
  * All Rights Reserved.
  *
@@ -15,9 +15,9 @@
  * The above copyright notice and this permission notice shall be
  * included in all copies or substantial portions of the Software.
  *
- * THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND, 
- * EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY 
- * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.  
+ * THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY
+ * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
  *
  * IN NO EVENT SHALL TOM WU BE LIABLE FOR ANY SPECIAL, INCIDENTAL,
  * INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND, OR ANY DAMAGES WHATSOEVER
@@ -37,7 +37,7 @@
  */
 
 var crypt = require('crypto');
-var _ = require('lodash');
+var isNumber = require('lodash.isnumber');
 
 // Bits per digit
 var dbits;
@@ -112,7 +112,7 @@ function am3(i, x, w, j, c, n) {
     return c;
 }
 
-// We need to select the fastest one that works in this environment. 
+// We need to select the fastest one that works in this environment.
 //if (j_lm && (navigator.appName == "Microsoft Internet Explorer")) {
 //	BigInteger.prototype.am = am2;
 //	dbits = 30;
@@ -832,7 +832,7 @@ function bnToBuffer(trimOrSize) {
     var res = new Buffer(this.toByteArray());
     if (trimOrSize === true && res[0] === 0) {
         res = res.slice(1);
-    } else if (_.isNumber(trimOrSize)) {
+    } else if (isNumber(trimOrSize)) {
         if (res.length > trimOrSize) {
             for (var i = 0; i < res.length - trimOrSize; i++) {
                 if (res[i] !== 0) {
diff --git a/package-lock.json b/package-lock.json
index 06d0a7b..a79de8e 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -467,10 +467,10 @@
       "integrity": "sha1-odePw6UEdMuAhF07O24dpJpEbo4=",
       "optional": true
     },
-    "lodash": {
-      "version": "4.17.10",
-      "resolved": "https://registry.npmjs.org/lodash/-/lodash-4.17.10.tgz",
-      "integrity": "sha512-UejweD1pDoXu+AD825lWwp4ZGtSwgnpZxb3JDViD7StjQz+Nb/6l093lx4OQ0foGWNRoc19mWy7BzL+UAK2iVg=="
+    "lodash.isnumber": {
+      "version": "3.0.3",
+      "resolved": "https://registry.npmjs.org/lodash.isnumber/-/lodash.isnumber-3.0.3.tgz",
+      "integrity": "sha1-POdoEMWSjQM1IwGsKHMX8RwLH/w="
     },
     "longest": {
       "version": "1.0.1",
diff --git a/package.json b/package.json
index 377a7ef..657964a 100644
--- a/package.json
+++ b/package.json
@@ -16,6 +16,6 @@
     "az-bunyan": "0.2.0-alpha.2",
     "azure-storage": "^2.8.2",
     "bunyan": "^1.8.12",
-    "lodash": "^4.17.10"
+    "lodash.isnumber": "^3.0.3"
   }
 }