diff --git a/platform/vcs-log/graph/src/com/intellij/vcs/log/graph/impl/print/EdgesInRowGenerator.java b/platform/vcs-log/graph/src/com/intellij/vcs/log/graph/impl/print/EdgesInRowGenerator.java
index 29d5e132cf87..7bfc56725359 100644
--- a/platform/vcs-log/graph/src/com/intellij/vcs/log/graph/impl/print/EdgesInRowGenerator.java
+++ b/platform/vcs-log/graph/src/com/intellij/vcs/log/graph/impl/print/EdgesInRowGenerator.java
@@ -34,7 +34,7 @@ public class EdgesInRowGenerator {
   @NotNull private final LinearGraph myGraph;
 
   @NotNull private final SLRUMap<Integer, GraphEdges> cacheNU = new SLRUMap<>(CACHE_SIZE, CACHE_SIZE * 2);
-  private final SLRUMap<Integer, GraphEdges> cacheND = new SLRUMap<>(CACHE_SIZE, CACHE_SIZE * 2);
+  @NotNull private final SLRUMap<Integer, GraphEdges> cacheND = new SLRUMap<>(CACHE_SIZE, CACHE_SIZE * 2);
 
   public EdgesInRowGenerator(@NotNull LinearGraph graph) {
     this(graph, 1000);