diff --git a/Libraries/Core/Timers/JSTimersExecution.js b/Libraries/Core/Timers/JSTimersExecution.js
index e5e386d4f..ee2275c33 100644
--- a/Libraries/Core/Timers/JSTimersExecution.js
+++ b/Libraries/Core/Timers/JSTimersExecution.js
@@ -47,7 +47,7 @@ const JSTimersExecution = {
   requestIdleCallbacks: [],
   identifiers: ([] : Array<null | {methodName: string}>),
 
-  errors: (null : ?[Error]),
+  errors: (null : ?Array<Error>),
 
   /**
    * Calls the callback associated with the ID. Also unregister that callback
@@ -112,9 +112,6 @@ const JSTimersExecution = {
       if (!JSTimersExecution.errors) {
         JSTimersExecution.errors = [e];
       } else {
-        /* $FlowFixMe(>=0.38.0 site=react_native_fb,react_native_oss) - Flow
-         * error detected during the deployment of v0.38.0. To see the error,
-         * remove this comment and run flow */
         JSTimersExecution.errors.push(e);
       }
     }
diff --git a/Libraries/NavigationExperimental/NavigationTransitioner.js b/Libraries/NavigationExperimental/NavigationTransitioner.js
index d174f98e1..7edf96faf 100644
--- a/Libraries/NavigationExperimental/NavigationTransitioner.js
+++ b/Libraries/NavigationExperimental/NavigationTransitioner.js
@@ -19,6 +19,8 @@ const React = require('React');
 const StyleSheet = require('StyleSheet');
 const View = require('View');
 
+const invariant = require('fbjs/lib/invariant');
+
 import type {
   NavigationAnimatedValue,
   NavigationLayout,
@@ -259,17 +261,17 @@ function buildTransitionProps(
     scenes,
   } = state;
 
-  /* $FlowFixMe(>=0.38.0 site=react_native_fb,react_native_oss) - Flow error
-   * detected during the deployment of v0.38.0. To see the error, remove this
-   * comment and run flow
-   */
+  const scene = scenes.find(isSceneActive);
+
+  invariant(scene, 'No active scene when building navigation transition props.');
+
   return {
     layout,
     navigationState,
     position,
     progress,
     scenes,
-    scene: scenes.find(isSceneActive),
+    scene
   };
 }
 
diff --git a/Libraries/Network/XMLHttpRequest.js b/Libraries/Network/XMLHttpRequest.js
index 30dce01b5..bf6d30191 100644
--- a/Libraries/Network/XMLHttpRequest.js
+++ b/Libraries/Network/XMLHttpRequest.js
@@ -121,7 +121,7 @@ class XMLHttpRequest extends EventTarget(...XHR_EVENTS) {
   upload: XMLHttpRequestEventTarget = new XMLHttpRequestEventTarget();
 
   _requestId: ?number;
-  _subscriptions: [any];
+  _subscriptions: Array<*>;
 
   _aborted: boolean = false;
   _cachedResponse: Response;
@@ -393,9 +393,6 @@ class XMLHttpRequest extends EventTarget(...XHR_EVENTS) {
     (this._subscriptions || []).forEach(sub => {
       sub.remove();
     });
-    /* $FlowFixMe(>=0.38.0 site=react_native_fb,react_native_oss) - Flow error
-     * detected during the deployment of v0.38.0. To see the error, remove this
-     * comment and run flow */
     this._subscriptions = [];
   }
 
@@ -460,44 +457,26 @@ class XMLHttpRequest extends EventTarget(...XHR_EVENTS) {
       !!this.onreadystatechange ||
       !!this.onprogress;
 
-    /* $FlowFixMe(>=0.38.0 site=react_native_fb,react_native_oss) - Flow error
-     * detected during the deployment of v0.38.0. To see the error, remove this
-     * comment and run flow */
     this._subscriptions.push(RCTNetworking.addListener(
       'didSendNetworkData',
       (args) => this.__didUploadProgress(...args)
     ));
-    /* $FlowFixMe(>=0.38.0 site=react_native_fb,react_native_oss) - Flow error
-     * detected during the deployment of v0.38.0. To see the error, remove this
-     * comment and run flow */
     this._subscriptions.push(RCTNetworking.addListener(
       'didReceiveNetworkResponse',
       (args) => this.__didReceiveResponse(...args)
     ));
-    /* $FlowFixMe(>=0.38.0 site=react_native_fb,react_native_oss) - Flow error
-     * detected during the deployment of v0.38.0. To see the error, remove this
-     * comment and run flow */
     this._subscriptions.push(RCTNetworking.addListener(
       'didReceiveNetworkData',
       (args) => this.__didReceiveData(...args)
     ));
-    /* $FlowFixMe(>=0.38.0 site=react_native_fb,react_native_oss) - Flow error
-     * detected during the deployment of v0.38.0. To see the error, remove this
-     * comment and run flow */
     this._subscriptions.push(RCTNetworking.addListener(
       'didReceiveNetworkIncrementalData',
       (args) => this.__didReceiveIncrementalData(...args)
     ));
-    /* $FlowFixMe(>=0.38.0 site=react_native_fb,react_native_oss) - Flow error
-     * detected during the deployment of v0.38.0. To see the error, remove this
-     * comment and run flow */
     this._subscriptions.push(RCTNetworking.addListener(
       'didReceiveNetworkDataProgress',
       (args) => this.__didReceiveDataProgress(...args)
     ));
-    /* $FlowFixMe(>=0.38.0 site=react_native_fb,react_native_oss) - Flow error
-     * detected during the deployment of v0.38.0. To see the error, remove this
-     * comment and run flow */
     this._subscriptions.push(RCTNetworking.addListener(
       'didCompleteNetworkResponse',
       (args) => this.__didCompleteResponse(...args)
diff --git a/Libraries/ReactNative/requireNativeComponent.js b/Libraries/ReactNative/requireNativeComponent.js
index 21bf0ae2d..c404e60bf 100644
--- a/Libraries/ReactNative/requireNativeComponent.js
+++ b/Libraries/ReactNative/requireNativeComponent.js
@@ -111,11 +111,7 @@ const TypeToDifferMap = {
   // (not yet implemented)
 };
 
-function processColorArray(colors: []): [] {
-  /* $FlowFixMe(>=0.38.0 site=react_native_fb,react_native_oss) - Flow error
-   * detected during the deployment of v0.38.0. To see the error, remove this
-   * comment and run flow
-   */
+function processColorArray(colors: ?Array<any>): ?Array<?number> {
   return colors && colors.map(processColor);
 }
 
diff --git a/Libraries/Renderer/src/renderers/shared/fiber/ReactChildFiber.js b/Libraries/Renderer/src/renderers/shared/fiber/ReactChildFiber.js
index e981a69fb..93839caed 100644
--- a/Libraries/Renderer/src/renderers/shared/fiber/ReactChildFiber.js
+++ b/Libraries/Renderer/src/renderers/shared/fiber/ReactChildFiber.js
@@ -73,7 +73,6 @@ function ChildReconciler(shouldClone) {
           return clone;
         }
         const child = createFiberFromElement(element, priority);
-        // $FlowFixMe(>=0.34.0)
         previousSibling.sibling = child;
         child.return = returnFiber;
         return child;
diff --git a/Libraries/Renderer/src/renderers/shared/fiber/ReactFiber.js b/Libraries/Renderer/src/renderers/shared/fiber/ReactFiber.js
index 700edd3a4..9d217797a 100644
--- a/Libraries/Renderer/src/renderers/shared/fiber/ReactFiber.js
+++ b/Libraries/Renderer/src/renderers/shared/fiber/ReactFiber.js
@@ -57,9 +57,6 @@ type Instance = {
 
 // A Fiber is work on a Component that needs to be done or was done. There can
 // be more than one per component.
-/* $FlowFixMe(>=0.38.0 site=react_native_fb,react_native_oss) - Flow error
- * detected during the deployment of v0.38.0. To see the error, remove this
- * comment and run flow */
 export type Fiber = Instance & {
 
   // The Fiber to return to after finishing processing this one.
@@ -249,7 +246,7 @@ exports.createFiberFromElement = function(element : ReactElement<*>, priorityLev
 };
 
 // $FlowFixMe(>=0.34.0)
-function createFiberFromElementType(type : mixed, key : null | string) {
+function createFiberFromElementType(type : Function | string | Fiber, key : null | string) {
   let fiber;
   if (typeof type === 'function') {
     fiber = shouldConstruct(type) ?
diff --git a/Libraries/Renderer/src/renderers/shared/fiber/ReactReifiedYield.js b/Libraries/Renderer/src/renderers/shared/fiber/ReactReifiedYield.js
index 06403b8ad..557fb0b50 100644
--- a/Libraries/Renderer/src/renderers/shared/fiber/ReactReifiedYield.js
+++ b/Libraries/Renderer/src/renderers/shared/fiber/ReactReifiedYield.js
@@ -20,16 +20,11 @@ var { createFiberFromElementType } = require('ReactFiber');
 export type ReifiedYield = { continuation: Fiber, props: Object };
 
 exports.createReifiedYield = function(yieldNode : ReactYield) : ReifiedYield {
-  var fiber = createFiberFromElementType(
-    yieldNode.continuation,
-    yieldNode.key
-  );
-  /* $FlowFixMe(>=0.38.0 site=react_native_fb,react_native_oss) - Flow error
-   * detected during the deployment of v0.38.0. To see the error, remove this
-   * comment and run flow
-   */
   return {
-    continuation: fiber,
+    continuation: createFiberFromElementType(
+      yieldNode.continuation,
+      yieldNode.key
+    ),
     props: yieldNode.props,
   };
 };
diff --git a/local-cli/server/middleware/heapCapture/src/AggrowTable.jsx b/local-cli/server/middleware/heapCapture/src/AggrowTable.jsx
index 66fcac3e8..8a54b2ba2 100644
--- a/local-cli/server/middleware/heapCapture/src/AggrowTable.jsx
+++ b/local-cli/server/middleware/heapCapture/src/AggrowTable.jsx
@@ -47,10 +47,7 @@ export default class AggrowTable extends React.Component {
   state: State;
 
   componentDidMount() {
-    /* $FlowFixMe(>=0.38.0 site=react_native_fb,react_native_oss) - Flow error
-     * detected during the deployment of v0.38.0. To see the error, remove this
-     * comment and run flow */
-    document.body.addEventListener('keydown', this.keydown);
+    document.body && document.body.addEventListener('keydown', this.keydown);
   }
 
   componentWillReceiveProps(nextProps: Props) {
@@ -64,10 +61,7 @@ export default class AggrowTable extends React.Component {
   }
 
   componentWillUnmount() {
-    /* $FlowFixMe(>=0.38.0 site=react_native_fb,react_native_oss) - Flow error
-     * detected during the deployment of v0.38.0. To see the error, remove this
-     * comment and run flow */
-    document.body.removeEventListener('keydown', this.keydown);
+    document.body && document.body.removeEventListener('keydown', this.keydown);
   }
 
   scroll = (e: SyntheticUIEvent) => {