diff --git a/packages/flutter/lib/src/widgets/async.dart b/packages/flutter/lib/src/widgets/async.dart
index b8aed1f94fc8d..d521bc3d19d31 100644
--- a/packages/flutter/lib/src/widgets/async.dart
+++ b/packages/flutter/lib/src/widgets/async.dart
@@ -200,7 +200,7 @@ class AsyncSnapshot<T> {
   /// and optionally either [data] or [error] with an optional [stackTrace]
   /// (but not both data and error).
   const AsyncSnapshot._(this.connectionState, this.data, this.error, this.stackTrace)
-    : assert(!(data != null && error != null)),
+    : assert(data == null || error == null),
       assert(stackTrace == null || error != null);
 
   /// Creates an [AsyncSnapshot] in [ConnectionState.none] with null data and error.