diff --git a/platform/vcs-tests/testSrc/com/intellij/openapi/vcs/PartialLineStatusTrackerTest.kt b/platform/vcs-tests/testSrc/com/intellij/openapi/vcs/PartialLineStatusTrackerTest.kt
index 625f8a2eca1d..953d018383b2 100644
--- a/platform/vcs-tests/testSrc/com/intellij/openapi/vcs/PartialLineStatusTrackerTest.kt
+++ b/platform/vcs-tests/testSrc/com/intellij/openapi/vcs/PartialLineStatusTrackerTest.kt
@@ -311,7 +311,10 @@ class PartialLineStatusTrackerTest : BaseLineStatusTrackerTestCase() {
 
           "N".replace("N2")
           "M".replace("M2")
+
+          vcsDocument.setReadOnly(false)
           vcsDocument.replaceString(0, 10, "XXXXX_IGNORED")
+          vcsDocument.setReadOnly(true)
 
           helper.applyChanges()