diff --git a/src/utils/__tests__/traverseAllChildren-test.js b/src/utils/__tests__/traverseAllChildren-test.js
index 91b51f0292..d998443b72 100644
--- a/src/utils/__tests__/traverseAllChildren-test.js
+++ b/src/utils/__tests__/traverseAllChildren-test.js
@@ -396,6 +396,8 @@ describe('traverseAllChildren', function() {
   });
 
   it('should use keys from entry iterables', function() {
+    spyOn(console, 'warn');
+
     var threeDivEntryIterable = {
       '@@iterator': function() {
         var i = 0;
@@ -445,6 +447,13 @@ describe('traverseAllChildren', function() {
       '.$#3:0',
       2
     );
+
+    expect(console.warn.argsForCall.length).toBe(1);
+    expect(console.warn.argsForCall[0][0]).toContain(
+      'Warning: Using Maps as children is not yet fully supported. It is an ' +
+      'experimental feature that might be removed. Convert it to a sequence ' +
+      '/ iterable of keyed ReactElements instead.'
+    );
   });
 
 });
diff --git a/src/utils/traverseAllChildren.js b/src/utils/traverseAllChildren.js
index da8fd53bb9..e547237a5a 100644
--- a/src/utils/traverseAllChildren.js
+++ b/src/utils/traverseAllChildren.js
@@ -17,6 +17,7 @@ var ReactInstanceHandles = require('ReactInstanceHandles');
 
 var getIteratorFn = require('getIteratorFn');
 var invariant = require('invariant');
+var warning = require('warning');
 
 var SEPARATOR = ReactInstanceHandles.SEPARATOR;
 var SUBSEPARATOR = ':';
@@ -34,6 +35,8 @@ var userProvidedKeyEscaperLookup = {
 
 var userProvidedKeyEscapeRegex = /[=.:]/g;
 
+var didWarnAboutMaps = false;
+
 function userProvidedKeyEscaper(match) {
   return userProvidedKeyEscaperLookup[match];
 }
@@ -158,6 +161,15 @@ function traverseAllChildrenImpl(
           );
         }
       } else {
+        if (__DEV__) {
+          warning(
+            didWarnAboutMaps,
+            'Using Maps as children is not yet fully supported. It is an ' +
+            'experimental feature that might be removed. Convert it to a ' +
+            'sequence / iterable of keyed ReactElements instead.'
+          );
+          didWarnAboutMaps = true;
+        }
         // Iterator will provide entry [k,v] tuples rather than values.
         while (!(step = iterator.next()).done) {
           var entry = step.value;