diff --git a/compiler/src/dotty/tools/dotc/transform/ExplicitOuter.scala b/compiler/src/dotty/tools/dotc/transform/ExplicitOuter.scala
index 00074a6ea81a..c1536022a2ac 100644
--- a/compiler/src/dotty/tools/dotc/transform/ExplicitOuter.scala
+++ b/compiler/src/dotty/tools/dotc/transform/ExplicitOuter.scala
@@ -176,8 +176,9 @@ object ExplicitOuter {
           if prefix == NoPrefix then outerCls.typeRef.appliedTo(outerCls.typeParams.map(_ => TypeBounds.empty))
           else prefix.widen)
     val info = if (flags.is(Method)) ExprType(target) else target
+    val currentNestingLevel = ctx.nestingLevel
     atPhaseNoEarlier(explicitOuterPhase.next) { // outer accessors are entered at explicitOuter + 1, should not be defined before.
-      newSymbol(owner, name, SyntheticArtifact | flags, info, coord = cls.coord)
+      newSymbol(owner, name, SyntheticArtifact | flags, info, coord = cls.coord, nestingLevel = currentNestingLevel)
     }
   }
 
diff --git a/tests/neg/i16343.scala b/tests/neg/i16343.scala
new file mode 100644
index 000000000000..d09ffcbe32c7
--- /dev/null
+++ b/tests/neg/i16343.scala
@@ -0,0 +1,2 @@
+class Issue16343:
+  class MyWorker extends javax.swing.SwingWorker[Unit, Unit] // error