diff --git a/compiler/cli/src/org/jetbrains/jet/cli/jvm/repl/ReplInterpreter.java b/compiler/cli/src/org/jetbrains/jet/cli/jvm/repl/ReplInterpreter.java
index 83f97b5128d..ef54201a6fc 100644
--- a/compiler/cli/src/org/jetbrains/jet/cli/jvm/repl/ReplInterpreter.java
+++ b/compiler/cli/src/org/jetbrains/jet/cli/jvm/repl/ReplInterpreter.java
@@ -83,8 +83,8 @@ public class ReplInterpreter {
     private int lineNumber = 0;
     @Nullable
     private JetScope lastLineScope;
-    private List<EarlierLine> earlierLines = Lists.newArrayList();
-    private List<String> previousIncompleteLines = Lists.newArrayList();
+    private final List<EarlierLine> earlierLines = Lists.newArrayList();
+    private final List<String> previousIncompleteLines = Lists.newArrayList();
     private final ReplClassLoader classLoader;
 
     @NotNull