--- a/testing/mochitest/tests/Harness_sanity/test_SpecialPowersPushPermissions.html
+++ b/testing/mochitest/tests/Harness_sanity/test_SpecialPowersPushPermissions.html
@@ -12,16 +12,21 @@
 const ALLOW_ACTION = SpecialPowers.Ci.nsIPermissionManager.ALLOW_ACTION;
 const DENY_ACTION = SpecialPowers.Ci.nsIPermissionManager.DENY_ACTION;
 const UNKNOWN_ACTION = SpecialPowers.Ci.nsIPermissionManager.UNKNOWN_ACTION;
 const PROMPT_ACTION = SpecialPowers.Ci.nsIPermissionManager.PROMPT_ACTION;
 const ACCESS_SESSION = SpecialPowers.Ci.nsICookiePermission.ACCESS_SESSION;
 const ACCESS_ALLOW_FIRST_PARTY_ONLY = SpecialPowers.Ci.nsICookiePermission.ACCESS_ALLOW_FIRST_PARTY_ONLY;
 const ACCESS_LIMIT_THIRD_PARTY = SpecialPowers.Ci.nsICookiePermission.ACCESS_LIMIT_THIRD_PARTY;
 
+const EXPIRE_TIME = SpecialPowers.Ci.nsIPermissionManager.EXPIRE_TIME;
+var start;
+const DELAY = 1000;
+SimpleTest.requestFlakyTimeout("untriaged");
+
 function starttest(){
   SpecialPowers.addPermission("pPROMPT", PROMPT_ACTION, document);
   SpecialPowers.addPermission("pALLOW", ALLOW_ACTION, document);
   SpecialPowers.addPermission("pDENY", DENY_ACTION, document);
   SpecialPowers.addPermission("pREMOVE", ALLOW_ACTION, document);
   SpecialPowers.addPermission("pSESSION", ACCESS_SESSION, document);
   SpecialPowers.addPermission("pFIRSTPARTY", ACCESS_ALLOW_FIRST_PARTY_ONLY, document);
   SpecialPowers.addPermission("pTHIRDPARTY", ACCESS_LIMIT_THIRD_PARTY, document);
@@ -131,16 +136,49 @@ function test6() {
     setTimeout(test6, 0);
   } else if (!SpecialPowers.testPermission('pFIRSTPARTY', UNKNOWN_ACTION, document)) {
     dump('/**** pFIRSTPARTY still set ****/\n');
     setTimeout(test6, 0);
   } else if (!SpecialPowers.testPermission('pTHIRDPARTY', UNKNOWN_ACTION, document)) {
     dump('/**** pTHIRDPARTY still set ****/\n');
     setTimeout(test6, 0);
   } else {
-    SimpleTest.finish();
+    test7();
   }
 }
+
+function test7() {
+  start = Number(Date.now());
+  SpecialPowers.addPermission('pEXPIRE', true, document, EXPIRE_TIME, start + DELAY);
+  testExpiredPermission(test8);
+}
+
+function test8() {
+  start = Number(Date.now());
+  SpecialPowers.pushPermissions([
+    { 'type': 'pEXPIRE',
+      'allow': true,
+      'expireType': EXPIRE_TIME,
+      'expireTime': start + DELAY,
+      'context': document
+    }], function() {
+      testExpiredPermission(SimpleTest.finish);
+    }
+  );
+}
+
+function testExpiredPermission(callback) {
+  var now = Number(Date.now());
+  if (now < start + DELAY) {
+    ok(SpecialPowers.testPermission('pEXPIRE', ALLOW_ACTION, document), 'unexpired permission is still there');
+    setTimeout(function() {testExpiredPermission(callback)}, DELAY);
+    return;
+  }
+
+  ok(!SpecialPowers.testPermission('pEXPIRE', ALLOW_ACTION, document), 'expired permission is cleared');
+
+  callback();
+}
 </script>
 </pre>
 </body>
 </html>
 

--- a/testing/specialpowers/content/SpecialPowersObserverAPI.js
+++ b/testing/specialpowers/content/SpecialPowersObserverAPI.js
@@ -313,17 +313,17 @@ SpecialPowersObserverAPI.prototype = {
       case "SPPermissionManager": {
         let msg = aMessage.json;
 
         let secMan = Services.scriptSecurityManager;
         let principal = secMan.getAppCodebasePrincipal(this._getURI(msg.url), msg.appId, msg.isInBrowserElement);
 
         switch (msg.op) {
           case "add":
-            Services.perms.addFromPrincipal(principal, msg.type, msg.permission);
+            Services.perms.addFromPrincipal(principal, msg.type, msg.permission, msg.expireType, msg.expireTime);
             break;
           case "remove":
             Services.perms.removeFromPrincipal(principal, msg.type);
             break;
           case "has":
             let hasPerm = Services.perms.testPermissionFromPrincipal(principal, msg.type);
             if (hasPerm == Ci.nsIPermissionManager.ALLOW_ACTION) 
               return true;

--- a/testing/specialpowers/content/specialpowersAPI.js
+++ b/testing/specialpowers/content/specialpowersAPI.js
@@ -801,24 +801,36 @@ SpecialPowersAPI.prototype = {
 
         if (permission.remove == true)
           perm = Ci.nsIPermissionManager.UNKNOWN_ACTION;
 
         if (originalValue == perm) {
           continue;
         }
 
-        var todo = {'op': 'add', 'type': permission.type, 'permission': perm, 'value': perm, 'url': url, 'appId': appId, 'isInBrowserElement': isInBrowserElement};
+        var todo = {'op': 'add',
+                    'type': permission.type,
+                    'permission': perm,
+                    'value': perm,
+                    'url': url,
+                    'appId': appId,
+                    'isInBrowserElement': isInBrowserElement,
+                    'expireType': (typeof permission.expireType === "number") ?
+                      permission.expireType : 0, // default: EXPIRE_NEVER
+                    'expireTime': (typeof permission.expireTime === "number") ?
+                      permission.expireTime : 0};
+
+        var cleanupTodo = Object.assign({}, todo);
+
         if (permission.remove == true)
           todo.op = 'remove';
 
         pendingPermissions.push(todo);
 
         /* Push original permissions value or clear into cleanup array */
-        var cleanupTodo = {'op': 'add', 'type': permission.type, 'permission': perm, 'value': perm, 'url': url, 'appId': appId, 'isInBrowserElement': isInBrowserElement};
         if (originalValue == Ci.nsIPermissionManager.UNKNOWN_ACTION) {
           cleanupTodo.op = 'remove';
         } else {
           cleanupTodo.value = originalValue;
           cleanupTodo.permission = originalValue;
         }
         cleanupPermissions.push(cleanupTodo);
     }
@@ -1861,17 +1873,17 @@ SpecialPowersAPI.prototype = {
       url = arg.url;
       appId = arg.appId;
       isInBrowserElement = arg.isInBrowserElement;
     }
 
     return [ url, appId, isInBrowserElement, isSystem ];
   },
 
-  addPermission: function(type, allow, arg) {
+  addPermission: function(type, allow, arg, expireType, expireTime) {
     let [url, appId, isInBrowserElement, isSystem] = this._getInfoFromPermissionArg(arg);
     if (isSystem) {
       return; // nothing to do
     }
 
     let permission;
     if (typeof allow !== 'boolean') {
       permission = allow;
@@ -1881,17 +1893,19 @@ SpecialPowersAPI.prototype = {
     }
 
     var msg = {
       'op': 'add',
       'type': type,
       'permission': permission,
       'url': url,
       'appId': appId,
-      'isInBrowserElement': isInBrowserElement
+      'isInBrowserElement': isInBrowserElement,
+      'expireType': (typeof expireType === "number") ? expireType : 0,
+      'expireTime': (typeof expireTime === "number") ? expireTime : 0
     };
 
     this._sendSyncMessage('SPPermissionManager', msg);
   },
 
   removePermission: function(type, arg) {
     let [url, appId, isInBrowserElement, isSystem] = this._getInfoFromPermissionArg(arg);
     if (isSystem) {