diff --git a/scripts/fiber/tests-passing-except-dev.txt b/scripts/fiber/tests-passing-except-dev.txt
index e5eb1addeff..db9abfa455f 100644
--- a/scripts/fiber/tests-passing-except-dev.txt
+++ b/scripts/fiber/tests-passing-except-dev.txt
@@ -105,11 +105,6 @@ src/renderers/__tests__/ReactComponentTreeHook-test.native.js
 * reports update counts
 * does not report top-level wrapper as a root
 
-src/renderers/__tests__/ReactCompositeComponent-test.js
-* should warn about `setState` in render
-* should warn about `setState` in getChildContext
-* should disallow nested render calls
-
 src/renderers/__tests__/ReactHostOperationHistoryHook-test.js
 * gets recorded for host roots
 * gets recorded for composite roots
diff --git a/scripts/fiber/tests-passing.txt b/scripts/fiber/tests-passing.txt
index 525a5586602..ca9ae8de0d6 100644
--- a/scripts/fiber/tests-passing.txt
+++ b/scripts/fiber/tests-passing.txt
@@ -577,6 +577,8 @@ src/renderers/__tests__/ReactCompositeComponent-test.js
 * should warn about `forceUpdate` on unmounted components
 * should warn about `setState` on unmounted components
 * should silently allow `setState`, not call cb on unmounting components
+* should warn about `setState` in render
+* should warn about `setState` in getChildContext
 * should cleanup even if render() fatals
 * should call componentWillUnmount before unmounting
 * should warn when shouldComponentUpdate() returns undefined
@@ -589,6 +591,7 @@ src/renderers/__tests__/ReactCompositeComponent-test.js
 * should pass context when re-rendered
 * unmasked context propagates through updates
 * should trigger componentWillReceiveProps for context changes
+* should disallow nested render calls
 * only renders once if updated in componentWillReceiveProps
 * only renders once if updated in componentWillReceiveProps when batching
 * should update refs if shouldComponentUpdate gives false
diff --git a/src/renderers/__tests__/ReactCompositeComponent-test.js b/src/renderers/__tests__/ReactCompositeComponent-test.js
index ff58a2465cc..03ad27e560b 100644
--- a/src/renderers/__tests__/ReactCompositeComponent-test.js
+++ b/src/renderers/__tests__/ReactCompositeComponent-test.js
@@ -1028,11 +1028,11 @@ describe('ReactCompositeComponent', () => {
 
     ReactTestUtils.renderIntoDocument(<Outer />);
     expectDev(console.error.calls.count()).toBe(1);
-    expectDev(console.error.calls.argsFor(0)[0]).toBe(
-      'Warning: _renderNewRootComponent(): Render methods should ' +
-      'be a pure function of props and state; triggering nested component ' +
-      'updates from render is not allowed. If necessary, trigger nested ' +
-      'updates in componentDidUpdate.\n\nCheck the render method of Outer.'
+    expectDev(console.error.calls.argsFor(0)[0]).toMatch(
+      'Render methods should be a pure function of props and state; ' +
+      'triggering nested component updates from render is not allowed. If ' +
+      'necessary, trigger nested updates in componentDidUpdate.\n\nCheck the ' +
+      'render method of Outer.'
     );
   });
 
diff --git a/src/renderers/shared/fiber/ReactDebugCurrentFiber.js b/src/renderers/shared/fiber/ReactDebugCurrentFiber.js
index d857e5f2dd3..6969cec6585 100644
--- a/src/renderers/shared/fiber/ReactDebugCurrentFiber.js
+++ b/src/renderers/shared/fiber/ReactDebugCurrentFiber.js
@@ -14,6 +14,8 @@
 
 import type { Fiber } from 'ReactFiber';
 
+type LifeCyclePhase = 'render' | 'getChildContext';
+
 if (__DEV__) {
   var getComponentName = require('getComponentName');
   var { getStackAddendumByWorkInProgressFiber } = require('ReactComponentTreeHook');
@@ -47,6 +49,8 @@ function getCurrentFiberStackAddendum() : string | null {
 
 var ReactDebugCurrentFiber = {
   current: (null : Fiber | null),
+  phase: (null : LifeCyclePhase | null),
+
   getCurrentFiberOwnerName,
   getCurrentFiberStackAddendum,
 };
diff --git a/src/renderers/shared/fiber/ReactFiberBeginWork.js b/src/renderers/shared/fiber/ReactFiberBeginWork.js
index 73c4870a300..b88be76bf0e 100644
--- a/src/renderers/shared/fiber/ReactFiberBeginWork.js
+++ b/src/renderers/shared/fiber/ReactFiberBeginWork.js
@@ -230,7 +230,9 @@ module.exports = function<T, P, I, TI, PI, C, CX, PL>(
 
     if (__DEV__) {
       ReactCurrentOwner.current = workInProgress;
+      ReactDebugCurrentFiber.phase = 'render';
       nextChildren = fn(nextProps, context);
+      ReactDebugCurrentFiber.phase = null;
     } else {
       nextChildren = fn(nextProps, context);
     }
@@ -279,7 +281,14 @@ module.exports = function<T, P, I, TI, PI, C, CX, PL>(
 
     // Rerender
     ReactCurrentOwner.current = workInProgress;
-    const nextChildren = instance.render();
+    let nextChildren;
+    if (__DEV__) {
+      ReactDebugCurrentFiber.phase = 'render';
+      nextChildren = instance.render();
+      ReactDebugCurrentFiber.phase = null;
+    } else {
+      nextChildren = instance.render();
+    }
     reconcileChildren(current, workInProgress, nextChildren);
     // Memoize props and state using the values we just used to render.
     // TODO: Restructure so we never read values from the instance.
diff --git a/src/renderers/shared/fiber/ReactFiberContext.js b/src/renderers/shared/fiber/ReactFiberContext.js
index 836bc79eb42..dbb7a43bd99 100644
--- a/src/renderers/shared/fiber/ReactFiberContext.js
+++ b/src/renderers/shared/fiber/ReactFiberContext.js
@@ -35,6 +35,7 @@ const {
 if (__DEV__) {
   var checkReactTypeSpec = require('checkReactTypeSpec');
   var ReactDebugCurrentFrame = require('ReactDebugCurrentFrame');
+  var ReactDebugCurrentFiber = require('ReactDebugCurrentFiber');
   var warnedAboutMissingGetChildContext = {};
 }
 
@@ -168,7 +169,14 @@ function processChildContext(fiber : Fiber, parentContext : Object, isReconcilin
     return parentContext;
   }
 
-  const childContext = instance.getChildContext();
+  let childContext;
+  if (__DEV__) {
+    ReactDebugCurrentFiber.phase = 'getChildContext';
+    childContext = instance.getChildContext();
+    ReactDebugCurrentFiber.phase = null;
+  } else {
+    childContext = instance.getChildContext();
+  }
   for (let contextKey in childContext) {
     invariant(
       contextKey in childContextTypes,
@@ -189,6 +197,7 @@ function processChildContext(fiber : Fiber, parentContext : Object, isReconcilin
     checkReactTypeSpec(childContextTypes, childContext, 'child context', name);
     ReactDebugCurrentFrame.current = null;
   }
+
   return {...parentContext, ...childContext};
 }
 exports.processChildContext = processChildContext;
diff --git a/src/renderers/shared/fiber/ReactFiberReconciler.js b/src/renderers/shared/fiber/ReactFiberReconciler.js
index 00bb5b7d856..3f910aa1d9a 100644
--- a/src/renderers/shared/fiber/ReactFiberReconciler.js
+++ b/src/renderers/shared/fiber/ReactFiberReconciler.js
@@ -32,6 +32,8 @@ var ReactFiberScheduler = require('ReactFiberScheduler');
 if (__DEV__) {
   var warning = require('warning');
   var ReactFiberInstrumentation = require('ReactFiberInstrumentation');
+  var ReactDebugCurrentFiber = require('ReactDebugCurrentFiber');
+  var { getComponentName } = require('ReactFiberTreeReflection');
 }
 
 var { findCurrentHostFiber } = require('ReactFiberTreeReflection');
@@ -144,6 +146,19 @@ module.exports = function<T, P, I, TI, PI, C, CX, PL>(
   } = ReactFiberScheduler(config);
 
   function scheduleTopLevelUpdate(current : Fiber, element : ReactNodeList, callback : ?Function) {
+    if (__DEV__) {
+      if (ReactDebugCurrentFiber.current !== null) {
+        warning(
+          ReactDebugCurrentFiber.phase !== 'render',
+          'Render methods should be a pure function of props and state; ' +
+          'triggering nested component updates from render is not allowed. ' +
+          'If necessary, trigger nested updates in componentDidUpdate.\n\n' +
+          'Check the render method of %s.',
+          getComponentName(ReactDebugCurrentFiber.current)
+        );
+      }
+    }
+
     const priorityLevel = getPriorityContext();
     const nextState = { element };
     callback = callback === undefined ? null : callback;
diff --git a/src/renderers/shared/fiber/ReactFiberScheduler.js b/src/renderers/shared/fiber/ReactFiberScheduler.js
index 258a254fab6..f0b8601da34 100644
--- a/src/renderers/shared/fiber/ReactFiberScheduler.js
+++ b/src/renderers/shared/fiber/ReactFiberScheduler.js
@@ -102,6 +102,26 @@ if (__DEV__) {
       ctor && (ctor.displayName || ctor.name) || 'ReactClass'
     );
   };
+
+  var warnAboutInvalidUpdates = function(instance : ReactClass<any>) {
+    switch (ReactDebugCurrentFiber.phase) {
+      case 'getChildContext':
+        warning(
+          false,
+          'setState(...): Cannot call setState() inside getChildContext()',
+        );
+        break;
+      case 'render':
+        warning(
+          false,
+          'Cannot update during an existing state transition (such as within ' +
+          '`render` or another component\'s constructor). Render methods should ' +
+          'be a pure function of props and state; constructor side-effects are ' +
+          'an anti-pattern, but can be moved to `componentWillMount`.'
+        );
+        break;
+    }
+  };
 }
 
 var timeHeuristicForUnitOfWork = 1;
@@ -859,6 +879,7 @@ module.exports = function<T, P, I, TI, PI, C, CX, PL>(config : HostConfig<T, P,
     ReactCurrentOwner.current = null;
     if (__DEV__) {
       ReactDebugCurrentFiber.current = null;
+      ReactDebugCurrentFiber.phase = null;
     }
     // It is no longer valid because this unit of work failed.
     nextUnitOfWork = null;
@@ -1102,6 +1123,13 @@ module.exports = function<T, P, I, TI, PI, C, CX, PL>(config : HostConfig<T, P,
       nextUnitOfWork = null;
     }
 
+    if (__DEV__) {
+      if (fiber.tag === ClassComponent) {
+        const instance = fiber.stateNode;
+        warnAboutInvalidUpdates(instance);
+      }
+    }
+
     let node = fiber;
     let shouldContinue = true;
     while (node !== null && shouldContinue) {