diff --git a/index.js b/index.js
index 6f2fcd5..a2f8eae 100644
--- a/index.js
+++ b/index.js
@@ -149,14 +149,14 @@ var validateSignature = function (message, cb, encoding) {
             return;
         }
         try {
-            if (verifier.verify(certificate, message['Signature'], 'base64')) {
-                cb(null, message);
-            } else {
-                cb(new Error('The message signature is invalid.'));
+            if (!verifier.verify(certificate, message['Signature'], 'base64')) {
+                throw new Error('The message signature is invalid.');
             }
         } catch (e) {
             cb(e);
+            return;
         }
+        cb(null, message);
     });
 };
 
diff --git a/package-lock.json b/package-lock.json
new file mode 100644
index 0000000..1007034
--- /dev/null
+++ b/package-lock.json
@@ -0,0 +1,316 @@
+{
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+      "dev": true
+    },
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+      "resolved": "http://registry.npmjs.org/chai/-/chai-3.5.0.tgz",
+      "integrity": "sha1-TQJjewZ/6Vi9v906QOxW/vc3Mkc=",
+      "dev": true,
+      "requires": {
+        "assertion-error": "1.1.0",
+        "deep-eql": "0.1.3",
+        "type-detect": "1.0.0"
+      }
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+      "version": "0.0.2",
+      "resolved": "https://registry.npmjs.org/charenc/-/charenc-0.0.2.tgz",
+      "integrity": "sha1-wKHS86cJLgN3S/qD8UwPxXkKhmc=",
+      "dev": true
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+      "resolved": "http://registry.npmjs.org/commander/-/commander-2.3.0.tgz",
+      "integrity": "sha1-/UMOiJgy7DU7ms0d4hfBHLPu+HM=",
+      "dev": true
+    },
+    "crypt": {
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+      "resolved": "https://registry.npmjs.org/crypt/-/crypt-0.0.2.tgz",
+      "integrity": "sha1-iNf/fsDfuG9xPch7u0LQRNPmxBs=",
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+      "dev": true
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+      "resolved": "https://registry.npmjs.org/escape-string-regexp/-/escape-string-regexp-1.0.2.tgz",
+      "integrity": "sha1-Tbwv5nTnGUnK8/smlc5/LcHZqNE=",
+      "dev": true
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+      "integrity": "sha1-Spc/Y1uRkPcV0QmH1cAP0oFevj0=",
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+      "integrity": "sha1-Dqd0NxXbjY3ixe3hd14bRayFwC8=",
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+          "dev": true
+        },
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+          "resolved": "http://registry.npmjs.org/mkdirp/-/mkdirp-0.3.0.tgz",
+          "integrity": "sha1-G79asbqCevI1dRQ0kEJkVfSB/h4=",
+          "dev": true
+        }
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+      "resolved": "http://registry.npmjs.org/lolex/-/lolex-1.3.2.tgz",
+      "integrity": "sha1-fD2mL/yzDw9agKJWbKJORdigHzE=",
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+      "integrity": "sha1-bUUk6LlV+V1PW1iFHOId1y+06VI=",
+      "dev": true
+    },
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+      "integrity": "sha1-U6s41f48iJG6RlMp6iP6wFQBJvk=",
+      "dev": true,
+      "requires": {
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+        "crypt": "0.0.2",
+        "is-buffer": "1.1.6"
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+}