diff --git a/README.md b/README.md
index 7fb8525539..a7ba39d9d5 100644
--- a/README.md
+++ b/README.md
@@ -132,7 +132,7 @@ The goal of an authentication flow is to [set an Okta session cookie on the user
 
   - `username` - User’s non-qualified short-name (e.g. dade.murphy) or unique fully-qualified login (e.g dade.murphy@example.com)
   - `password` - The password of the user
-  - `sendFingerprint` -  Enabling this will send a `X-Device-Fingerprint` header. Defaults to `false`
+  - `sendFingerprint` - Enabling this will send a `X-Device-Fingerprint` header. Defaults to `false`
 
 ```javascript
 authClient.signIn({
diff --git a/lib/tx.js b/lib/tx.js
index aba77843c3..e1a1a6ccf9 100644
--- a/lib/tx.js
+++ b/lib/tx.js
@@ -48,8 +48,8 @@ function transactionExists(sdk) {
   return !!sdk.tx.exists._getCookie(config.STATE_TOKEN_COOKIE_NAME);
 }
 
-function postToTransaction(sdk, url, body, options) {
-  return http.post(sdk, url, body, options)
+function postToTransaction(sdk, url, args, options) {
+  return http.post(sdk, url, args, options)
     .then(function(res) {
       return new AuthTransaction(sdk, res);
     });
diff --git a/test/spec/fingerprint.js b/test/spec/fingerprint.js
index 4754dfe541..a6ec8e4e38 100644
--- a/test/spec/fingerprint.js
+++ b/test/spec/fingerprint.js
@@ -177,6 +177,35 @@ define(function(require) {
       }
     });
 
+    util.itMakesCorrectRequestResponse({
+      title: 'does not attach fingerprint to signIn requests if addFingerprint is false',
+      setup: {
+        uri: 'http://example.okta.com',
+        calls: [
+          {
+            request: {
+              method: 'post',
+              uri: '/api/v1/authn',
+              data: { username: 'not', password: 'real' },
+              headers: {
+                'Accept': 'application/json',
+                'Content-Type': 'application/json',
+                'X-Okta-User-Agent-Extended': 'okta-auth-js-' + packageJson.version
+              }
+            },
+            response: 'success'
+          }
+        ]
+      },
+      execute: function (test) {
+        return test.oa.signIn({
+          username: 'not',
+          password: 'real',
+          sendFingerprint: false
+        });
+      }
+    });
+
     it('fails signIn request if fingerprinting fails', function(done) {
       return setup({ firstMessage: 'invalidMessageContent' })
       .signIn({