diff --git a/pkg/front_end/lib/src/fasta/builder/prefix_builder.dart b/pkg/front_end/lib/src/fasta/builder/prefix_builder.dart
index c986a85eb2d..66b116ebc17 100644
--- a/pkg/front_end/lib/src/fasta/builder/prefix_builder.dart
+++ b/pkg/front_end/lib/src/fasta/builder/prefix_builder.dart
@@ -30,8 +30,11 @@ class PrefixBuilder extends BuilderImpl {
 
   final LoadLibraryBuilder? loadLibraryBuilder;
 
+  final bool isWildcard;
+
   PrefixBuilder(this.name, this.deferred, this.parent, this.loadLibraryBuilder,
-      this.charOffset, this.importIndex) {
+      this.charOffset, this.importIndex)
+      : isWildcard = name == '_' {
     assert(deferred == (loadLibraryBuilder != null),
         "LoadLibraryBuilder must be provided iff prefix is deferred.");
     if (loadLibraryBuilder != null) {
diff --git a/pkg/front_end/lib/src/fasta/kernel/body_builder.dart b/pkg/front_end/lib/src/fasta/kernel/body_builder.dart
index 04d16c69a45..63d56c12dd6 100644
--- a/pkg/front_end/lib/src/fasta/kernel/body_builder.dart
+++ b/pkg/front_end/lib/src/fasta/kernel/body_builder.dart
@@ -3515,6 +3515,14 @@ class BodyBuilder extends StackListenerImpl
           memberBuilder.parent, memberBuilder.member, null);
     } else if (declaration is PrefixBuilder) {
       assert(prefix == null);
+      // Wildcard import prefixes are non-binding and cannot be used.
+      if (libraryFeatures.wildcardVariables.isEnabled &&
+          declaration.isWildcard) {
+        // TODO(kallentu): Provide a helpful error related to wildcard prefixes.
+        return new UnresolvedNameGenerator(this, nameToken,
+            new Name(declaration.name, libraryBuilder.nameOrigin),
+            unresolvedReadKind: UnresolvedKind.Unknown);
+      }
       return new PrefixUseGenerator(this, nameToken, declaration);
     } else if (declaration is LoadLibraryBuilder) {
       return new LoadLibraryGenerator(this, nameToken, declaration);
diff --git a/pkg/front_end/testcases/wildcard_variables/import_prefix.dart b/pkg/front_end/testcases/wildcard_variables/import_prefix.dart
new file mode 100644
index 00000000000..12132e403db
--- /dev/null
+++ b/pkg/front_end/testcases/wildcard_variables/import_prefix.dart
@@ -0,0 +1,11 @@
+// Copyright (c) 2024, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import 'dart:collection' as _;
+
+test() {
+  _.Queue<int>();
+  Queue<int>();
+  [1].firstOrNull;
+}
diff --git a/pkg/front_end/testcases/wildcard_variables/import_prefix.dart.strong.expect b/pkg/front_end/testcases/wildcard_variables/import_prefix.dart.strong.expect
new file mode 100644
index 00000000000..322536e2656
--- /dev/null
+++ b/pkg/front_end/testcases/wildcard_variables/import_prefix.dart.strong.expect
@@ -0,0 +1,27 @@
+library;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/wildcard_variables/import_prefix.dart:8:3: Error: Undefined name '_'.
+//   _.Queue<int>();
+//   ^
+//
+// pkg/front_end/testcases/wildcard_variables/import_prefix.dart:9:3: Error: Method not found: 'Queue'.
+//   Queue<int>();
+//   ^^^^^
+//
+import self as self;
+import "dart:core" as core;
+import "dart:collection" as col;
+
+import "dart:collection" as _;
+
+static method test() → dynamic {
+  invalid-expression "pkg/front_end/testcases/wildcard_variables/import_prefix.dart:8:3: Error: Undefined name '_'.
+  _.Queue<int>();
+  ^"{dynamic}.Queue<core::int>();
+  invalid-expression "pkg/front_end/testcases/wildcard_variables/import_prefix.dart:9:3: Error: Method not found: 'Queue'.
+  Queue<int>();
+  ^^^^^";
+  col::IterableExtensions|get#firstOrNull<core::int>(<core::int>[1]);
+}
diff --git a/pkg/front_end/testcases/wildcard_variables/import_prefix.dart.strong.modular.expect b/pkg/front_end/testcases/wildcard_variables/import_prefix.dart.strong.modular.expect
new file mode 100644
index 00000000000..322536e2656
--- /dev/null
+++ b/pkg/front_end/testcases/wildcard_variables/import_prefix.dart.strong.modular.expect
@@ -0,0 +1,27 @@
+library;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/wildcard_variables/import_prefix.dart:8:3: Error: Undefined name '_'.
+//   _.Queue<int>();
+//   ^
+//
+// pkg/front_end/testcases/wildcard_variables/import_prefix.dart:9:3: Error: Method not found: 'Queue'.
+//   Queue<int>();
+//   ^^^^^
+//
+import self as self;
+import "dart:core" as core;
+import "dart:collection" as col;
+
+import "dart:collection" as _;
+
+static method test() → dynamic {
+  invalid-expression "pkg/front_end/testcases/wildcard_variables/import_prefix.dart:8:3: Error: Undefined name '_'.
+  _.Queue<int>();
+  ^"{dynamic}.Queue<core::int>();
+  invalid-expression "pkg/front_end/testcases/wildcard_variables/import_prefix.dart:9:3: Error: Method not found: 'Queue'.
+  Queue<int>();
+  ^^^^^";
+  col::IterableExtensions|get#firstOrNull<core::int>(<core::int>[1]);
+}
diff --git a/pkg/front_end/testcases/wildcard_variables/import_prefix.dart.strong.outline.expect b/pkg/front_end/testcases/wildcard_variables/import_prefix.dart.strong.outline.expect
new file mode 100644
index 00000000000..f5a4c94a90e
--- /dev/null
+++ b/pkg/front_end/testcases/wildcard_variables/import_prefix.dart.strong.outline.expect
@@ -0,0 +1,7 @@
+library;
+import self as self;
+
+import "dart:collection" as _;
+
+static method test() → dynamic
+  ;
diff --git a/pkg/front_end/testcases/wildcard_variables/import_prefix.dart.strong.transformed.expect b/pkg/front_end/testcases/wildcard_variables/import_prefix.dart.strong.transformed.expect
new file mode 100644
index 00000000000..26d2c519b56
--- /dev/null
+++ b/pkg/front_end/testcases/wildcard_variables/import_prefix.dart.strong.transformed.expect
@@ -0,0 +1,27 @@
+library;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/wildcard_variables/import_prefix.dart:8:3: Error: Undefined name '_'.
+//   _.Queue<int>();
+//   ^
+//
+// pkg/front_end/testcases/wildcard_variables/import_prefix.dart:9:3: Error: Method not found: 'Queue'.
+//   Queue<int>();
+//   ^^^^^
+//
+import self as self;
+import "dart:core" as core;
+import "dart:collection" as col;
+
+import "dart:collection" as _;
+
+static method test() → dynamic {
+  invalid-expression "pkg/front_end/testcases/wildcard_variables/import_prefix.dart:8:3: Error: Undefined name '_'.
+  _.Queue<int>();
+  ^"{dynamic}.Queue<core::int>();
+  invalid-expression "pkg/front_end/testcases/wildcard_variables/import_prefix.dart:9:3: Error: Method not found: 'Queue'.
+  Queue<int>();
+  ^^^^^";
+  col::IterableExtensions|get#firstOrNull<core::int>(core::_GrowableList::_literal1<core::int>(1));
+}
diff --git a/pkg/front_end/testcases/wildcard_variables/import_prefix.dart.textual_outline.expect b/pkg/front_end/testcases/wildcard_variables/import_prefix.dart.textual_outline.expect
new file mode 100644
index 00000000000..638e0bf39d4
--- /dev/null
+++ b/pkg/front_end/testcases/wildcard_variables/import_prefix.dart.textual_outline.expect
@@ -0,0 +1,3 @@
+import 'dart:collection' as _;
+
+test() {}
diff --git a/pkg/front_end/testcases/wildcard_variables/import_prefix.dart.textual_outline_modelled.expect b/pkg/front_end/testcases/wildcard_variables/import_prefix.dart.textual_outline_modelled.expect
new file mode 100644
index 00000000000..638e0bf39d4
--- /dev/null
+++ b/pkg/front_end/testcases/wildcard_variables/import_prefix.dart.textual_outline_modelled.expect
@@ -0,0 +1,3 @@
+import 'dart:collection' as _;
+
+test() {}
diff --git a/tests/language/wildcard_variables/import/import_error_test.dart b/tests/language/wildcard_variables/import/import_error_test.dart
index 65f8e68433a..0d6278548b9 100644
--- a/tests/language/wildcard_variables/import/import_error_test.dart
+++ b/tests/language/wildcard_variables/import/import_error_test.dart
@@ -15,21 +15,21 @@ main() {
   _.topLevel;
 //^
 // [analyzer] unspecified
-// [cfe] unspecified
+// [cfe] Undefined name '_'.
 
   _.C(value);
 //^
 // [analyzer] unspecified
-// [cfe] unspecified
+// [cfe] Undefined name '_'.
 
   // Private extensions can't be used.
   value.bar;
-//^
-// [analyzer] unspecified
-// [cfe] unspecified
+//      ^^^
+// [analyzer] COMPILE_TIME_ERROR.UNDEFINED_GETTER
+// [cfe] The getter 'bar' isn't defined for the class 'String'.
 
   value.fn;
-//^
-// [analyzer] unspecified
-// [cfe] unspecified
+//      ^^
+// [analyzer] COMPILE_TIME_ERROR.UNDEFINED_GETTER
+// [cfe] The getter 'fn' isn't defined for the class 'String'.
 }