diff --git a/platform/diff-impl/src/com/intellij/openapi/vcs/ex/DocumentTracker.kt b/platform/diff-impl/src/com/intellij/openapi/vcs/ex/DocumentTracker.kt
index 1b3108b0f3fc..d9dffd9f0dc7 100644
--- a/platform/diff-impl/src/com/intellij/openapi/vcs/ex/DocumentTracker.kt
+++ b/platform/diff-impl/src/com/intellij/openapi/vcs/ex/DocumentTracker.kt
@@ -370,7 +370,7 @@ class DocumentTracker : Disposable {
 
     private fun getAffectedRange(line1: Int, oldLine2: Int, newLine2: Int, e: DocumentEvent): Triple<Int, Int, Int> {
       val afterLength = newLine2 - line1
-      val beforeLength = line2 - line1
+      val beforeLength = oldLine2 - line1
 
       // Whole line insertion / deletion
       if (e.oldLength == 0 && e.newLength != 0) {