diff --git a/packages/react-dom/src/__tests__/ReactDOMInput-test.js b/packages/react-dom/src/__tests__/ReactDOMInput-test.js
index 5afa9dcf7aa..3710fa40081 100644
--- a/packages/react-dom/src/__tests__/ReactDOMInput-test.js
+++ b/packages/react-dom/src/__tests__/ReactDOMInput-test.js
@@ -400,14 +400,20 @@ describe('ReactDOMInput', () => {
 
   it('should display "true" for `defaultValue` of `true`', () => {
     let stub = <input type="text" defaultValue={true} />;
-    const node = ReactDOM.render(stub, container);
+    let node;
+    expect(() => (node = ReactDOM.render(stub, container))).toWarnDev(
+      'Received `true` for a non-boolean attribute `defaultValue`',
+    );
 
     expect(node.value).toBe('true');
   });
 
   it('should display "false" for `defaultValue` of `false`', () => {
     let stub = <input type="text" defaultValue={false} />;
-    const node = ReactDOM.render(stub, container);
+    let node;
+    expect(() => (node = ReactDOM.render(stub, container))).toWarnDev(
+      'Received `false` for a non-boolean attribute `defaultValue`',
+    );
 
     expect(node.value).toBe('false');
   });
@@ -1641,22 +1647,25 @@ describe('ReactDOMInput', () => {
     });
 
     it('treats initial Symbol defaultValue as an empty string', function() {
-      ReactDOM.render(<input defaultValue={Symbol('foobar')} />, container);
+      expect(() =>
+        ReactDOM.render(<input defaultValue={Symbol('foobar')} />, container),
+      ).toWarnDev('Invalid value for prop `defaultValue`');
+
       const node = container.firstChild;
 
       expect(node.value).toBe('');
       expect(node.getAttribute('value')).toBe('');
-      // TODO: we should warn here.
     });
 
     it('treats updated Symbol defaultValue as an empty string', function() {
       ReactDOM.render(<input defaultValue="foo" />, container);
-      ReactDOM.render(<input defaultValue={Symbol('foobar')} />, container);
+      expect(() =>
+        ReactDOM.render(<input defaultValue={Symbol('foobar')} />, container),
+      ).toWarnDev('Invalid value for prop `defaultValue`');
       const node = container.firstChild;
 
       expect(node.value).toBe('foo');
       expect(node.getAttribute('value')).toBe('');
-      // TODO: we should warn here.
     });
   });
 
@@ -1689,22 +1698,24 @@ describe('ReactDOMInput', () => {
     });
 
     it('treats initial function defaultValue as an empty string', function() {
-      ReactDOM.render(<input defaultValue={() => {}} />, container);
+      expect(() =>
+        ReactDOM.render(<input defaultValue={() => {}} />, container),
+      ).toWarnDev('Invalid value for prop `defaultValue`');
       const node = container.firstChild;
 
       expect(node.value).toBe('');
       expect(node.getAttribute('value')).toBe('');
-      // TODO: we should warn here.
     });
 
     it('treats updated function defaultValue as an empty string', function() {
       ReactDOM.render(<input defaultValue="foo" />, container);
-      ReactDOM.render(<input defaultValue={() => {}} />, container);
+      expect(() =>
+        ReactDOM.render(<input defaultValue={() => {}} />, container),
+      ).toWarnDev('Invalid value for prop `defaultValue`');
       const node = container.firstChild;
 
       expect(node.value).toBe('foo');
       expect(node.getAttribute('value')).toBe('');
-      // TODO: we should warn here.
     });
   });
 
diff --git a/packages/react-dom/src/__tests__/ReactDOMTextarea-test.js b/packages/react-dom/src/__tests__/ReactDOMTextarea-test.js
index fa5d717974a..0c40c1ff36f 100644
--- a/packages/react-dom/src/__tests__/ReactDOMTextarea-test.js
+++ b/packages/react-dom/src/__tests__/ReactDOMTextarea-test.js
@@ -63,7 +63,10 @@ describe('ReactDOMTextarea', () => {
 
   it('should display "false" for `defaultValue` of `false`', () => {
     const stub = <textarea defaultValue={false} />;
-    const node = renderTextarea(stub);
+    let node;
+    expect(() => (node = renderTextarea(stub))).toWarnDev(
+      'Received `false` for a non-boolean attribute `defaultValue`',
+    );
 
     expect(node.value).toBe('false');
   });
diff --git a/packages/react-dom/src/shared/DOMProperty.js b/packages/react-dom/src/shared/DOMProperty.js
index cef4609497f..b65d445a42b 100644
--- a/packages/react-dom/src/shared/DOMProperty.js
+++ b/packages/react-dom/src/shared/DOMProperty.js
@@ -51,6 +51,7 @@ export type PropertyInfo = {|
   +mustUseProperty: boolean,
   +propertyName: string,
   +type: PropertyType,
+  +shouldWarnInDev: boolean,
 |};
 
 /* eslint-disable max-len */
@@ -115,7 +116,13 @@ export function shouldRemoveAttributeWithWarning(
   propertyInfo: PropertyInfo | null,
   isCustomComponentTag: boolean,
 ): boolean {
-  if (propertyInfo !== null && propertyInfo.type === RESERVED) {
+  // Do not validate data types for reserved props
+  // (excluding defaultValue)
+  if (
+    propertyInfo !== null &&
+    propertyInfo.type === RESERVED &&
+    !propertyInfo.shouldWarnInDev
+  ) {
     return false;
   }
   switch (typeof value) {
@@ -186,6 +193,7 @@ function PropertyInfoRecord(
   mustUseProperty: boolean,
   attributeName: string,
   attributeNamespace: string | null,
+  shouldWarnInDev: boolean = false,
 ) {
   this.acceptsBooleans =
     type === BOOLEANISH_STRING ||
@@ -196,6 +204,7 @@ function PropertyInfoRecord(
   this.mustUseProperty = mustUseProperty;
   this.propertyName = name;
   this.type = type;
+  this.shouldWarnInDev = shouldWarnInDev;
 }
 
 // When adding attributes to this list, be sure to also add them to
@@ -223,6 +232,7 @@ const properties = {};
     false, // mustUseProperty
     name, // attributeName
     null, // attributeNamespace
+    name === 'defaultValue', // shouldWarnInDev
   );
 });
 
diff --git a/packages/react-dom/src/shared/ReactDOMUnknownPropertyHook.js b/packages/react-dom/src/shared/ReactDOMUnknownPropertyHook.js
index 9e7fda4e6cd..100cb22755e 100644
--- a/packages/react-dom/src/shared/ReactDOMUnknownPropertyHook.js
+++ b/packages/react-dom/src/shared/ReactDOMUnknownPropertyHook.js
@@ -214,12 +214,6 @@ if (__DEV__) {
       return true;
     }
 
-    // Now that we've validated casing, do not validate
-    // data types for reserved props
-    if (isReserved) {
-      return true;
-    }
-
     // Warn when a known attribute is a bad type
     if (shouldRemoveAttributeWithWarning(name, value, propertyInfo, false)) {
       warnedProperties[name] = true;