diff --git a/src/Compilers/CSharp/Portable/FlowAnalysis/AbstractFlowPass.cs b/src/Compilers/CSharp/Portable/FlowAnalysis/AbstractFlowPass.cs
index f92de3ecb0b2f..cb5d99d4602b3 100644
--- a/src/Compilers/CSharp/Portable/FlowAnalysis/AbstractFlowPass.cs
+++ b/src/Compilers/CSharp/Portable/FlowAnalysis/AbstractFlowPass.cs
@@ -3041,7 +3041,9 @@ public override BoundNode VisitConditionalReceiver(BoundConditionalReceiver node
 
         public override BoundNode VisitLoweredIsPatternExpression(BoundLoweredIsPatternExpression node)
         {
+            var savedState = this.State.Clone();
             VisitStatements(node.Statements);
+            this.State = savedState;
             return null;
         }