diff --git a/lib/internal/bootstrap/node.js b/lib/internal/bootstrap/node.js
index a6ef700143ee9f..237a1b96922aef 100644
--- a/lib/internal/bootstrap/node.js
+++ b/lib/internal/bootstrap/node.js
@@ -39,9 +39,9 @@
 setupPrepareStackTrace();
 
 const {
+  Array,
   ArrayPrototypeConcat,
-  ArrayPrototypeFilter,
-  ArrayPrototypeMap,
+  ArrayPrototypeFill,
   FunctionPrototypeCall,
   JSONParse,
   ObjectDefineProperty,
@@ -49,7 +49,6 @@ const {
   ObjectGetPrototypeOf,
   ObjectPreventExtensions,
   ObjectSetPrototypeOf,
-  ObjectValues,
   ReflectGet,
   ReflectSet,
   SymbolToStringTag,
@@ -156,13 +155,12 @@ const rawMethods = internalBinding('process_methods');
   process._getActiveHandles = rawMethods._getActiveHandles;
 
   process.getActiveResourcesInfo = function() {
+    const timerCounts = internalTimers.getTimerCounts();
     return ArrayPrototypeConcat(
       rawMethods._getActiveRequestsInfo(),
       rawMethods._getActiveHandlesInfo(),
-      ArrayPrototypeMap(
-        ArrayPrototypeFilter(ObjectValues(internalTimers.activeTimersMap),
-                             ({ resource }) => resource.hasRef()),
-        ({ type }) => type));
+      ArrayPrototypeFill(new Array(timerCounts.timeoutCount), 'Timeout'),
+      ArrayPrototypeFill(new Array(timerCounts.immediateCount), 'Immediate'));
   };
 
   // TODO(joyeecheung): remove these
diff --git a/lib/internal/timers.js b/lib/internal/timers.js
index 8edff995326a01..2441d7b194a72b 100644
--- a/lib/internal/timers.js
+++ b/lib/internal/timers.js
@@ -139,12 +139,6 @@ const kRefed = Symbol('refed');
 // Create a single linked list instance only once at startup
 const immediateQueue = new ImmediateList();
 
-// Object map containing timers
-//
-// - key = asyncId
-// - value = { type, resource }
-const activeTimersMap = ObjectCreate(null);
-
 let nextExpiry = Infinity;
 let refCount = 0;
 
@@ -166,7 +160,6 @@ function initAsyncResource(resource, type) {
     resource[trigger_async_id_symbol] = getDefaultTriggerAsyncId();
   if (initHooksExist())
     emitInit(asyncId, type, triggerAsyncId, resource);
-  activeTimersMap[asyncId] = { type, resource };
 }
 
 // Timer constructor function.
@@ -478,7 +471,6 @@ function getTimerCallbacks(runNextTicks) {
 
         if (destroyHooksExist())
           emitDestroy(asyncId);
-        delete activeTimersMap[asyncId];
 
         outstandingQueue.head = immediate = immediate._idleNext;
       }
@@ -551,7 +543,6 @@ function getTimerCallbacks(runNextTicks) {
 
           if (destroyHooksExist())
             emitDestroy(asyncId);
-          delete activeTimersMap[asyncId];
         }
         continue;
       }
@@ -580,7 +571,6 @@ function getTimerCallbacks(runNextTicks) {
 
           if (destroyHooksExist())
             emitDestroy(asyncId);
-          delete activeTimersMap[asyncId];
         }
       }
 
@@ -648,6 +638,13 @@ class Immediate {
   }
 }
 
+function getTimerCounts() {
+  return {
+    timeoutCount: refCount,
+    immediateCount: immediateInfo[kRefCount],
+  };
+}
+
 module.exports = {
   TIMEOUT_MAX,
   kTimeout: Symbol('timeout'), // For hiding Timeouts on other internals.
@@ -670,9 +667,9 @@ module.exports = {
   active,
   unrefActive,
   insert,
-  activeTimersMap,
   timerListMap,
   timerListQueue,
   decRefCount,
-  incRefCount
+  incRefCount,
+  getTimerCounts,
 };
diff --git a/lib/timers.js b/lib/timers.js
index 51e8e69d172022..a4543fea1df6bc 100644
--- a/lib/timers.js
+++ b/lib/timers.js
@@ -45,7 +45,6 @@ const {
   kRefed,
   kHasPrimitive,
   getTimerDuration,
-  activeTimersMap,
   timerListMap,
   timerListQueue,
   immediateQueue,
@@ -88,7 +87,6 @@ function unenroll(item) {
   // Fewer checks may be possible, but these cover everything.
   if (destroyHooksExist() && item[async_id_symbol] !== undefined)
     emitDestroy(item[async_id_symbol]);
-  delete activeTimersMap[item[async_id_symbol]];
 
   L.remove(item);
 
@@ -331,7 +329,6 @@ function clearImmediate(immediate) {
   if (destroyHooksExist() && immediate[async_id_symbol] !== undefined) {
     emitDestroy(immediate[async_id_symbol]);
   }
-  delete activeTimersMap[immediate[async_id_symbol]];
 
   immediate._onImmediate = null;