diff --git a/Libraries/Core/InitializeCore.js b/Libraries/Core/InitializeCore.js
index 3e6ebb6807..e2a624e468 100644
--- a/Libraries/Core/InitializeCore.js
+++ b/Libraries/Core/InitializeCore.js
@@ -54,7 +54,7 @@ if (!global.process.env.NODE_ENV) {
 // Setup the Systrace profiling hooks if necessary
 if (global.__RCTProfileIsProfiling) {
   const Systrace = require('Systrace');
-  Systrace.installReactHook(true);
+  Systrace.installReactHook();
   Systrace.setEnabled(true);
 }
 
diff --git a/Libraries/Performance/Systrace.js b/Libraries/Performance/Systrace.js
index 002c12f34f..1abedee7c1 100644
--- a/Libraries/Performance/Systrace.js
+++ b/Libraries/Performance/Systrace.js
@@ -32,7 +32,6 @@ let _asyncCookie = 0;
 const _markStack = [];
 let _markStackIndex = -1;
 let _canInstallReactHook = false;
-let _useFiber = false;
 
 // Implements a subset of User Timing API necessary for React measurements.
 // https://developer.mozilla.org/en-US/docs/Web/API/User_Timing_API
@@ -98,54 +97,13 @@ const userTimingPolyfill = __DEV__ ? {
   },
 } : null;
 
-// A hook to get React Stack markers in Systrace.
-const reactDebugToolHook = __DEV__ ? {
-  onBeforeMountComponent(debugID) {
-    const ReactComponentTreeHook = require('ReactGlobalSharedState').ReactComponentTreeHook;
-    const displayName = ReactComponentTreeHook.getDisplayName(debugID);
-    Systrace.beginEvent(`ReactReconciler.mountComponent(${displayName})`);
-  },
-  onMountComponent(debugID) {
-    Systrace.endEvent();
-  },
-  onBeforeUpdateComponent(debugID) {
-    const ReactComponentTreeHook = require('ReactGlobalSharedState').ReactComponentTreeHook;
-    const displayName = ReactComponentTreeHook.getDisplayName(debugID);
-    Systrace.beginEvent(`ReactReconciler.updateComponent(${displayName})`);
-  },
-  onUpdateComponent(debugID) {
-    Systrace.endEvent();
-  },
-  onBeforeUnmountComponent(debugID) {
-    const ReactComponentTreeHook = require('ReactGlobalSharedState').ReactComponentTreeHook;
-    const displayName = ReactComponentTreeHook.getDisplayName(debugID);
-    Systrace.beginEvent(`ReactReconciler.unmountComponent(${displayName})`);
-  },
-  onUnmountComponent(debugID) {
-    Systrace.endEvent();
-  },
-  onBeginLifeCycleTimer(debugID, timerType) {
-    const ReactComponentTreeHook = require('ReactGlobalSharedState').ReactComponentTreeHook;
-    const displayName = ReactComponentTreeHook.getDisplayName(debugID);
-    Systrace.beginEvent(`${displayName}.${timerType}()`);
-  },
-  onEndLifeCycleTimer(debugID, timerType) {
-    Systrace.endEvent();
-  },
-} : null;
-
 const Systrace = {
-  installReactHook(useFiber: boolean) {
+  installReactHook() {
     if (_enabled) {
       if (__DEV__) {
-        if (useFiber) {
-          global.performance = userTimingPolyfill;
-        } else {
-          require('ReactDebugTool').addHook(reactDebugToolHook);
-        }
+        global.performance = userTimingPolyfill;
       }
     }
-    _useFiber = useFiber;
     _canInstallReactHook = true;
   },
 
@@ -158,17 +116,8 @@ const Systrace = {
           global.nativeTraceEndLegacy && global.nativeTraceEndLegacy(TRACE_TAG_JS_VM_CALLS);
         }
         if (_canInstallReactHook) {
-          if (_useFiber) {
-            if (enabled && global.performance === undefined) {
-              global.performance = userTimingPolyfill;
-            }
-          } else {
-            const ReactDebugTool = require('ReactDebugTool');
-            if (enabled) {
-              ReactDebugTool.addHook(reactDebugToolHook);
-            } else {
-              ReactDebugTool.removeHook(reactDebugToolHook);
-            }
+          if (enabled && global.performance === undefined) {
+            global.performance = userTimingPolyfill;
           }
         }
       }
@@ -240,7 +189,7 @@ const Systrace = {
   attachToRelayProfiler(relayProfiler: RelayProfiler) {
     relayProfiler.attachProfileHandler('*', (name, state?) => {
       if (state != null && state.queryName !== undefined) {
-        name += '_' + state.queryName
+        name += '_' + state.queryName;
       }
       const cookie = Systrace.beginAsyncEvent(name);
       return () => {