diff --git a/build.js b/build.js
index c8e6a3822..eedbff1fa 100755
--- a/build.js
+++ b/build.js
@@ -2210,7 +2210,7 @@
             '  var args,',
             '      result,',
             '      thisArg,',
-            '      timeoutId;',
+            '      timeoutId = null;',
             '',
             '  function delayed() {',
             '    timeoutId = null;',
@@ -2567,8 +2567,8 @@
             '  var args,',
             '      result,',
             '      thisArg,',
-            '      timeoutId,',
-            '      lastCalled = 0;',
+            '      lastCalled = 0,',
+            '      timeoutId = null;',
             '',
             '  function trailingCall() {',
             '    lastCalled = new Date;',
diff --git a/lodash.js b/lodash.js
index e00d47118..6de91505d 100644
--- a/lodash.js
+++ b/lodash.js
@@ -4639,8 +4639,8 @@
       var args,
           result,
           thisArg,
-          timeoutId,
           callCount = 0,
+          timeoutId = null,
           trailing = true;
 
       function delayed() {
@@ -4660,6 +4660,9 @@
       return function() {
         args = arguments;
         thisArg = this;
+
+        // avoid issues with Titanium and `undefined` timeout ids
+        // https://github.com/appcelerator/titanium_mobile/blob/3_1_0_GA/android/titanium/src/java/ti/modules/titanium/TitaniumModule.java#L185-L192
         clearTimeout(timeoutId);
 
         if (leading && ++callCount < 2) {
@@ -4868,9 +4871,9 @@
       var args,
           result,
           thisArg,
-          timeoutId,
           lastCalled = 0,
           leading = true,
+          timeoutId = null,
           trailing = true;
 
       function trailingCall() {