diff --git a/platform/lang-api/src/com/intellij/codeInsight/editorActions/moveUpDown/LineRange.java b/platform/lang-api/src/com/intellij/codeInsight/editorActions/moveUpDown/LineRange.java
index 0b58917e447e..b9fba8d2bf57 100644
--- a/platform/lang-api/src/com/intellij/codeInsight/editorActions/moveUpDown/LineRange.java
+++ b/platform/lang-api/src/com/intellij/codeInsight/editorActions/moveUpDown/LineRange.java
@@ -33,6 +33,7 @@ public class LineRange {
   public LineRange(final int startLine, final int endLine) {
     this.startLine = startLine;
     this.endLine = endLine;
+    LOG.assertTrue(startLine > 0, "Negative start line");
     if (startLine > endLine) {
       LOG.error("start > end: start=" + startLine+"; end="+endLine);
     }