diff --git a/packages/react-reconciler/src/ReactChildFiber.new.js b/packages/react-reconciler/src/ReactChildFiber.new.js
index 992544cba8e62..831fa2a3e30be 100644
--- a/packages/react-reconciler/src/ReactChildFiber.new.js
+++ b/packages/react-reconciler/src/ReactChildFiber.new.js
@@ -937,6 +937,22 @@ function ChildReconciler(shouldTrackSideEffects) {
           );
         }
         didWarnAboutGenerators = true;
+      } else {
+        // Warn about using one-shot iterators as children
+        const isOneShotIterator =
+          iteratorFn.call(newChildrenIterable) === newChildrenIterable;
+        if (isOneShotIterator) {
+          if (!didWarnAboutOneShotIterators) {
+            console.error(
+              'Using a TOOD-understandable-term as children is unsupported and will likely yield ' +
+                'unexpected results because enumerating a TOOD-understandable-term mutates it. ' +
+                'You may convert it to an array with `Array.from()` or the ' +
+                '`[...spread]` operator before rendering. Keep in mind ' +
+                'you might need to polyfill these features for older browsers.',
+            );
+          }
+          didWarnAboutOneShotIterators = true;
+        }
       }
 
       // Warn about using Maps as children
@@ -950,22 +966,6 @@ function ChildReconciler(shouldTrackSideEffects) {
         didWarnAboutMaps = true;
       }
 
-      // Warn about using one-shot iterators as children
-      const isOneShotIterator =
-        iteratorFn.call(newChildrenIterable) === newChildrenIterable;
-      if (isOneShotIterator) {
-        if (!didWarnAboutOneShotIterators) {
-          console.error(
-            'Using a TOOD-understandable-term as children is unsupported and will likely yield ' +
-              'unexpected results because enumerating a TOOD-understandable-term mutates it. ' +
-              'You may convert it to an array with `Array.from()` or the ' +
-              '`[...spread]` operator before rendering. Keep in mind ' +
-              'you might need to polyfill these features for older browsers.',
-          );
-        }
-        didWarnAboutOneShotIterators = true;
-      }
-
       // First, validate keys.
       // We'll get a different iterator later for the main pass.
       const newChildren = iteratorFn.call(newChildrenIterable);
diff --git a/packages/react-reconciler/src/ReactChildFiber.old.js b/packages/react-reconciler/src/ReactChildFiber.old.js
index 5f9d050452a25..a4f80d16f17e6 100644
--- a/packages/react-reconciler/src/ReactChildFiber.old.js
+++ b/packages/react-reconciler/src/ReactChildFiber.old.js
@@ -937,6 +937,22 @@ function ChildReconciler(shouldTrackSideEffects) {
           );
         }
         didWarnAboutGenerators = true;
+      } else {
+        // Warn about using one-shot iterators as children
+        const isOneShotIterator =
+          iteratorFn.call(newChildrenIterable) === newChildrenIterable;
+        if (isOneShotIterator) {
+          if (!didWarnAboutOneShotIterators) {
+            console.error(
+              'Using a TOOD-understandable-term as children is unsupported and will likely yield ' +
+                'unexpected results because enumerating a TOOD-understandable-term mutates it. ' +
+                'You may convert it to an array with `Array.from()` or the ' +
+                '`[...spread]` operator before rendering. Keep in mind ' +
+                'you might need to polyfill these features for older browsers.',
+            );
+          }
+          didWarnAboutOneShotIterators = true;
+        }
       }
 
       // Warn about using Maps as children
@@ -950,22 +966,6 @@ function ChildReconciler(shouldTrackSideEffects) {
         didWarnAboutMaps = true;
       }
 
-      // Warn about using one-shot iterators as children
-      const isOneShotIterator =
-        iteratorFn.call(newChildrenIterable) === newChildrenIterable;
-      if (isOneShotIterator) {
-        if (!didWarnAboutOneShotIterators) {
-          console.error(
-            'Using a TOOD-understandable-term as children is unsupported and will likely yield ' +
-              'unexpected results because enumerating a TOOD-understandable-term mutates it. ' +
-              'You may convert it to an array with `Array.from()` or the ' +
-              '`[...spread]` operator before rendering. Keep in mind ' +
-              'you might need to polyfill these features for older browsers.',
-          );
-        }
-        didWarnAboutOneShotIterators = true;
-      }
-
       // First, validate keys.
       // We'll get a different iterator later for the main pass.
       const newChildren = iteratorFn.call(newChildrenIterable);