diff --git a/plugins/stream-debugger/src/com/intellij/debugger/streams/ui/impl/CollectionTree.java b/plugins/stream-debugger/src/com/intellij/debugger/streams/ui/impl/CollectionTree.java
index 882a4c59f4fb..fb2eda2f93e5 100644
--- a/plugins/stream-debugger/src/com/intellij/debugger/streams/ui/impl/CollectionTree.java
+++ b/plugins/stream-debugger/src/com/intellij/debugger/streams/ui/impl/CollectionTree.java
@@ -274,14 +274,18 @@ public class CollectionTree extends XDebuggerTree implements TraceContainer {
 
     int topIndex = 0;
     int bottomIndex = 1;
-    int topY = getRowBounds(rows[topIndex]).y;
+    Rectangle rowBounds = getRowBounds(rows[topIndex]);
+    if (rowBounds == null) return visibleRect;
+    int topY = rowBounds.y;
 
     final Result result = new Result();
     while (bottomIndex < rows.length) {
       final int nextY = getRowBounds(rows[bottomIndex]).y;
       while (nextY - topY > height) {
         topIndex++;
-        topY = getRowBounds(rows[topIndex]).y;
+        rowBounds = getRowBounds(rows[topIndex]);
+        if (rowBounds == null) return visibleRect;
+        topY = rowBounds.y;
       }
 
       if (bottomIndex - topIndex > result.count()) {