diff --git a/tlatools/org.lamport.tlatools/src/tlc2/tool/TLCState.java b/tlatools/org.lamport.tlatools/src/tlc2/tool/TLCState.java
index 9e37cc0155..d9240be698 100644
--- a/tlatools/org.lamport.tlatools/src/tlc2/tool/TLCState.java
+++ b/tlatools/org.lamport.tlatools/src/tlc2/tool/TLCState.java
@@ -86,6 +86,8 @@ public IValue lookup(String var) {
 
   protected TLCState deepCopy(TLCState copy) {
 	  copy.level = this.level;
+	  copy.workerId = this.workerId;
+	  copy.uid = this.uid;
 	  return copy;
   }