diff --git a/compiler/src/dotty/tools/dotc/typer/RefChecks.scala b/compiler/src/dotty/tools/dotc/typer/RefChecks.scala
index 37bdde5b0559..6e9d4caa7f6a 100644
--- a/compiler/src/dotty/tools/dotc/typer/RefChecks.scala
+++ b/compiler/src/dotty/tools/dotc/typer/RefChecks.scala
@@ -1186,7 +1186,7 @@ object RefChecks {
 
   /** Check that classes extending experimental classes or nested in experimental classes have the @experimental annotation. */
   private def checkExperimentalInheritance(cls: ClassSymbol)(using Context): Unit =
-    if !cls.hasAnnotation(defn.ExperimentalAnnot) then
+    if !cls.isAnonymousClass && !cls.hasAnnotation(defn.ExperimentalAnnot) then
       cls.info.parents.find(_.typeSymbol.isExperimental) match
         case Some(parent) =>
           report.error(em"extension of experimental ${parent.typeSymbol} must have @experimental annotation", cls.srcPos)
diff --git a/tests/neg-custom-args/no-experimental/i13091.scala b/tests/neg-custom-args/no-experimental/i13091.scala
new file mode 100644
index 000000000000..b2e0c1844540
--- /dev/null
+++ b/tests/neg-custom-args/no-experimental/i13091.scala
@@ -0,0 +1,5 @@
+import annotation.experimental
+
+@experimental class Foo // error: use of @experimental is experimental ...
+
+def test: Unit = new Foo // error: class Foo is marked @experimental ...
diff --git a/tests/pos/i13091.scala b/tests/pos/i13091.scala
new file mode 100644
index 000000000000..fa255cd6c08f
--- /dev/null
+++ b/tests/pos/i13091.scala
@@ -0,0 +1,3 @@
+import annotation.experimental
+@experimental class Foo
+val foo = new Foo