diff --git a/toolkit/modules/Http.jsm b/toolkit/modules/Http.jsm
index 12eb44477a74..807250cd4598 100644
--- a/toolkit/modules/Http.jsm
+++ b/toolkit/modules/Http.jsm
@@ -34,14 +34,12 @@ function httpRequest(aUrl, aOptions) {
   let xhr = Cc["@mozilla.org/xmlextras/xmlhttprequest;1"]
               .createInstance(Ci.nsIXMLHttpRequest);
   xhr.mozBackgroundRequest = true; // no error dialogs
-  let hasPostData = "postData" in aOptions && aOptions.postData;
-  xhr.open("method" in aOptions ? aOptions.method :
-           (hasPostData ? "POST" : "GET"), aUrl);
+  xhr.open(aOptions.method || (aOptions.postData ? "POST" : "GET"), aUrl);
   xhr.channel.loadFlags = Ci.nsIChannel.LOAD_ANONYMOUS | // don't send cookies
                           Ci.nsIChannel.LOAD_BYPASS_CACHE |
                           Ci.nsIChannel.INHIBIT_CACHING;
   xhr.onerror = function(aProgressEvent) {
-    if ("onError" in aOptions) {
+    if (aOptions.onError) {
       // adapted from toolkit/mozapps/extensions/nsBlocklistService.js
       let request = aProgressEvent.target;
       let status;
@@ -58,10 +56,10 @@ function httpRequest(aUrl, aOptions) {
       aOptions.onError(statusText, null, this);
     }
   };
-  xhr.onload = function (aRequest) {
+  xhr.onload = function(aRequest) {
     try {
       let target = aRequest.target;
-      if ("logger" in aOptions)
+      if (aOptions.logger)
         aOptions.logger.debug("Received response: " + target.responseText);
       if (target.status < 200 || target.status >= 300) {
         let errorText = target.responseText;
@@ -69,23 +67,23 @@ function httpRequest(aUrl, aOptions) {
           errorText = target.statusText;
         throw target.status + " - " + errorText;
       }
-      if ("onLoad" in aOptions)
+      if (aOptions.onLoad)
         aOptions.onLoad(target.responseText, this);
     } catch (e) {
       Cu.reportError(e);
-      if ("onError" in aOptions)
+      if (aOptions.onError)
         aOptions.onError(e, aRequest.target.responseText, this);
     }
   };
 
-  if ("headers" in aOptions) {
+  if (aOptions.headers) {
     aOptions.headers.forEach(function(header) {
       xhr.setRequestHeader(header[0], header[1]);
     });
   }
 
   // Handle adding postData as defined above.
-  let POSTData = hasPostData ? aOptions.postData : "";
+  let POSTData = aOptions.postData || "";
   if (Array.isArray(POSTData)) {
     xhr.setRequestHeader("Content-Type",
                          "application/x-www-form-urlencoded; charset=utf-8");
@@ -93,7 +91,7 @@ function httpRequest(aUrl, aOptions) {
                        .join("&");
   }
 
-  if ("logger" in aOptions) {
+  if (aOptions.logger) {
     aOptions.logger.log("sending request to " + aUrl + " (POSTData = " +
                         POSTData + ")");
   }
diff --git a/toolkit/modules/tests/xpcshell/test_Http.js b/toolkit/modules/tests/xpcshell/test_Http.js
index 6b51a7843328..3cf8f00769dc 100644
--- a/toolkit/modules/tests/xpcshell/test_Http.js
+++ b/toolkit/modules/tests/xpcshell/test_Http.js
@@ -142,6 +142,18 @@ add_test(function test_GetData() {
   httpRequest(kGetUrl, options);
 });
 
+add_test(function test_OptionalParameters() {
+  let options = {
+    onLoad: null,
+    onError: null,
+    logger: null
+  };
+  // Just make sure that nothing throws when doing this (i.e. httpRequest
+  // doesn't try to access null options).
+  httpRequest(kGetUrl, options);
+  run_next_test();
+});
+
 function run_test() {
   // Set up a mock HTTP server to serve a success page.
   server = new HttpServer();