diff --git a/compiler/frontend/src/org/jetbrains/jet/lang/resolve/BindingTraceContext.java b/compiler/frontend/src/org/jetbrains/jet/lang/resolve/BindingTraceContext.java
index 312437f670f..2d8af172dbb 100644
--- a/compiler/frontend/src/org/jetbrains/jet/lang/resolve/BindingTraceContext.java
+++ b/compiler/frontend/src/org/jetbrains/jet/lang/resolve/BindingTraceContext.java
@@ -30,8 +30,8 @@ public class BindingTraceContext implements BindingTrace {
     private final List<Diagnostic> diagnostics = Lists.newArrayList();
 
     // These flags are used for debugging of "Rewrite at slice..." exceptions
-    private final static boolean TRACK_REWRITES = false;
-    private final static boolean TRACK_WITH_STACK_TRACES = true;
+    /* package */ final static boolean TRACK_REWRITES = false;
+    /* package */ final static boolean TRACK_WITH_STACK_TRACES = true;
 
     private final MutableSlicedMap map;
 
diff --git a/compiler/frontend/src/org/jetbrains/jet/lang/resolve/DelegatingBindingTrace.java b/compiler/frontend/src/org/jetbrains/jet/lang/resolve/DelegatingBindingTrace.java
index 11390ed33e5..9a015f60763 100644
--- a/compiler/frontend/src/org/jetbrains/jet/lang/resolve/DelegatingBindingTrace.java
+++ b/compiler/frontend/src/org/jetbrains/jet/lang/resolve/DelegatingBindingTrace.java
@@ -30,8 +30,10 @@ import java.util.List;
 import java.util.Map;
 
 public class DelegatingBindingTrace implements BindingTrace {
+    @SuppressWarnings("ConstantConditions")
+    private final MutableSlicedMap map = BindingTraceContext.TRACK_REWRITES ? new TrackingSlicedMap(BindingTraceContext.TRACK_WITH_STACK_TRACES) : SlicedMapImpl.create();
+
     private final BindingContext parentContext;
-    private final MutableSlicedMap map = SlicedMapImpl.create();
     private final List<Diagnostic> diagnostics = Lists.newArrayList();
     private final String name;