diff --git a/lib/IAMClient.js b/lib/IAMClient.js
index 1fecca43..563e5e32 100644
--- a/lib/IAMClient.js
+++ b/lib/IAMClient.js
@@ -413,7 +413,7 @@ class IAMClient {
             })
 
             .on('end', () => {
-                this.handleResponse(res, ret, callback);
+                this.handleResponse(res, ret, logger, callback);
             });
         });
         req.on('error', err => {
@@ -476,21 +476,41 @@ class IAMClient {
      * @param {object} res - response to the request
      * @param {string} ret - content (data and/or metadata) returned after the
      *                       request has been processed
+     * @param {object} log - werelogs request logger
      * @param {IAMClient~requestCallback} callback - callback
      * @returns {undefined}
      */
-    handleResponse(res, ret, callback) {
+    handleResponse(res, ret, log, callback) {
         this.getObj(ret, (err, obj) => {
             if (err) {
+                if (log) {
+                    log.error('error from vault',
+                        { error: err, method: 'IAMClient.handleResponse' });
+                }
                 return callback(err, null, res.statusCode);
             }
             /* This is not an error */
             if (res.statusCode < 400) {
                 return callback(null, obj, res.statusCode);
             }
+
             // Load the error from errors(arsenal)
-            return callback(
-                errors[obj.ErrorResponse.Error.Code], null, res.statusCode);
+            if (obj && obj.ErrorResponse && obj.ErrorResponse.Error) {
+                if (log) {
+                    log.debug('error from vault',
+                        { error: obj, method: 'IAMClient.handleResponse' });
+                }
+                return callback(
+                    errors[obj.ErrorResponse.Error.Code], null, res.statusCode);
+            }
+            if (log) {
+                log.error('unable to translate error from vault', {
+                    error: obj,
+                    method: 'IAMClient.handleResponse',
+                });
+            }
+            return callback(errors.InternalError
+                .customizeDescription('unable to translate error from vault'));
         });
     }
 }
diff --git a/tests/unit/handleResponse.js b/tests/unit/handleResponse.js
new file mode 100644
index 00000000..ca12d9d6
--- /dev/null
+++ b/tests/unit/handleResponse.js
@@ -0,0 +1,26 @@
+'use strict'; // eslint-disable-line
+// const http = require('http');
+const assert = require('assert');
+const errors = require('arsenal').errors;
+const IAMClient = require('../../lib/IAMClient.js');
+
+const log = { error() {} };
+const res = { statusCode: 400 };
+const ret = '<Response><Code>foo</Code></Response>';
+const expErr = errors.InternalError
+    .customizeDescription('unable to translate error from vault');
+
+describe('handling unrecognized error syntax', () => {
+    let client;
+
+    beforeEach('create client', () => client = new IAMClient('127.0.0.1'));
+
+    afterEach('delete client', () => { client = undefined; });
+
+    it('should return Internal Error for unrecognized errors', done => {
+        client.handleResponse(res, ret, log, err => {
+            assert.deepStrictEqual(err, expErr);
+            return done();
+        });
+    });
+});