diff --git a/python/python-psi-impl/resources/intellij.python.psi.impl.xml b/python/python-psi-impl/resources/intellij.python.psi.impl.xml
index 8e823ed9f305..e830886909b5 100644
--- a/python/python-psi-impl/resources/intellij.python.psi.impl.xml
+++ b/python/python-psi-impl/resources/intellij.python.psi.impl.xml
@@ -189,6 +189,8 @@
     <annotator language="Python" implementationClass="com.jetbrains.python.validation.PyBuiltinHighlightingAnnotator"/>
     <annotator language="Python" implementationClass="com.jetbrains.python.validation.UnsupportedFeatures"/>
 
+    <daemon.changeLocalityDetector implementation="com.jetbrains.python.inspections.PyChangeLocalityDetector"/>
+
     <localInspection language="Python" shortName="PyUnusedLocalInspection" suppressId="PyUnusedLocal" bundle="messages.PyPsiBundle" key="INSP.NAME.unused" groupKey="INSP.GROUP.python" enabledByDefault="true" level="WEAK WARNING" implementationClass="com.jetbrains.python.inspections.unusedLocal.PyUnusedLocalInspection"/>
     <localInspection language="Python" shortName="PyRedundantParenthesesInspection" suppressId="PyRedundantParentheses" bundle="messages.PyPsiBundle" key="INSP.NAME.redundant.parentheses" groupKey="INSP.GROUP.python" enabledByDefault="true" level="WEAK WARNING" implementationClass="com.jetbrains.python.inspections.PyRedundantParenthesesInspection"/>
     <localInspection language="Python" shortName="PySimplifyBooleanCheckInspection" suppressId="PySimplifyBooleanCheck" bundle="messages.PyPsiBundle" key="INSP.NAME.check.can.be.simplified" groupKey="INSP.GROUP.python" enabledByDefault="true" level="WEAK WARNING" implementationClass="com.jetbrains.python.inspections.PySimplifyBooleanCheckInspection"/>
diff --git a/python/python-psi-impl/src/com/jetbrains/python/inspections/PyChangeLocalityDetector.kt b/python/python-psi-impl/src/com/jetbrains/python/inspections/PyChangeLocalityDetector.kt
new file mode 100644
index 000000000000..9270fda4f319
--- /dev/null
+++ b/python/python-psi-impl/src/com/jetbrains/python/inspections/PyChangeLocalityDetector.kt
@@ -0,0 +1,18 @@
+package com.jetbrains.python.inspections
+
+import com.intellij.codeInsight.daemon.ChangeLocalityDetector
+import com.intellij.psi.PsiElement
+import com.intellij.psi.PsiWhiteSpace
+import com.jetbrains.python.psi.PyFile
+
+class PyChangeLocalityDetector : ChangeLocalityDetector {
+  override fun getChangeHighlightingDirtyScopeFor(changedElement: PsiElement): PsiElement? {
+    if (changedElement is PsiWhiteSpace) {
+      val parent = changedElement.parent
+      if (parent is PyFile) {
+        return parent
+      }
+    }
+    return null
+  }
+}
\ No newline at end of file
diff --git a/python/testSrc/com/jetbrains/python/inspections/PyChangeLocalityDetectorTest.kt b/python/testSrc/com/jetbrains/python/inspections/PyChangeLocalityDetectorTest.kt
new file mode 100644
index 000000000000..8b367383d1c6
--- /dev/null
+++ b/python/testSrc/com/jetbrains/python/inspections/PyChangeLocalityDetectorTest.kt
@@ -0,0 +1,98 @@
+package com.jetbrains.python.inspections
+
+import com.intellij.psi.PsiElement
+import com.intellij.psi.util.PsiTreeUtil
+import com.jetbrains.python.fixtures.PyTestCase
+import com.jetbrains.python.psi.PyFile
+import junit.framework.TestCase
+
+class PyChangeLocalityDetectorTest : PyTestCase() {
+
+  fun `test top level function body change`() = checkChangeScope("""
+        def f():
+            <selection>x = 1</selection>
+    """, null)
+
+  fun `test top level function whitespace at the start change`() = checkChangeScope("""
+        <selection>
+        </selection>def f():
+            x = 1
+        
+        def bar():
+            pass
+    """.trimIndent(), """
+        
+        
+        def f():
+            x = 1
+        
+        def bar():
+            pass
+    """.trimIndent())
+
+  fun `test top level function whitespace at the end change`() = checkChangeScope("""
+        def f():
+            x = 1<selection>
+        
+        </selection>def bar():
+            pass
+    """.trimIndent(), """
+        def f():
+            x = 1
+        
+        def bar():
+            pass
+    """.trimIndent())
+
+  fun `test top level class whitespace at the end change`() = checkChangeScope("""
+        class A:
+            x = 1<selection>
+        
+        </selection>def bar():
+            pass
+    """.trimIndent(), """
+        class A:
+            x = 1
+        
+        def bar():
+            pass
+    """.trimIndent())
+
+  private fun checkChangeScope(text: String, expectedScope: String?) {
+    myFixture.configureByText("main.py", text)
+
+    val selectionModel = myFixture.editor.selectionModel
+    assertTrue("changed item has to be specified in <selection></selection>", selectionModel.hasSelection())
+
+    var element = PsiTreeUtil.findElementOfClassAtRange(
+      myFixture.file,
+      selectionModel.selectionStart,
+      selectionModel.selectionEnd,
+      PsiElement::class.java
+    ) ?: error("No PsiElement at selection range")
+
+    val changeLocalityDetector = PyChangeLocalityDetector()
+
+    /**
+     * Emulate [com.intellij.codeInsight.daemon.impl.PsiChangeHandler.updateByChange] logic
+     * by walking up the tree and calling [com.intellij.codeInsight.daemon.ChangeLocalityDetector.getChangeHighlightingDirtyScopeFor]
+     * until non-null is returned
+     */
+    while (element !is PyFile) {
+      val dirtyScope = changeLocalityDetector.getChangeHighlightingDirtyScopeFor(element)
+      if (dirtyScope != null) {
+        if (expectedScope == null) {
+          throw IllegalStateException("scope was calculated when no scope was expected")
+        }
+
+        TestCase.assertEquals(expectedScope.trimIndent(), dirtyScope.text)
+        return
+      }
+      element = element.parent
+    }
+
+    if (expectedScope != null) {
+      throw IllegalStateException("scope wasn't calculated")
+    }
+  }
+}