diff --git a/platform/platform-impl/src/com/intellij/openapi/editor/ex/util/EditorUtil.java b/platform/platform-impl/src/com/intellij/openapi/editor/ex/util/EditorUtil.java
index d0f01dac2554..6f502f49655a 100644
--- a/platform/platform-impl/src/com/intellij/openapi/editor/ex/util/EditorUtil.java
+++ b/platform/platform-impl/src/com/intellij/openapi/editor/ex/util/EditorUtil.java
@@ -301,7 +301,8 @@ public class EditorUtil {
     boolean useOptimization = true;
     boolean hasNonTabs = false;
     boolean hasTabs = false;
-    for (int i = start; i < end; i++) {
+    int scanEndOffset = Math.min(end, start + columnNumber + 1);
+    for (int i = start; i < scanEndOffset; i++) {
       char c = text.charAt(i);
       if (debugBuffer != null) {
         debugBuffer.append(String.format("Found symbol '%c' at the offset %d%n", c, i));