diff --git a/python/src/com/jetbrains/python/codeInsight/imports/PyImportOptimizer.java b/python/src/com/jetbrains/python/codeInsight/imports/PyImportOptimizer.java
index 75d3e40aed81..07d921bd2f60 100644
--- a/python/src/com/jetbrains/python/codeInsight/imports/PyImportOptimizer.java
+++ b/python/src/com/jetbrains/python/codeInsight/imports/PyImportOptimizer.java
@@ -22,10 +22,7 @@ import com.intellij.openapi.project.Project;
 import com.intellij.openapi.util.Comparing;
 import com.intellij.openapi.util.Couple;
 import com.intellij.openapi.util.text.StringUtil;
-import com.intellij.psi.PsiComment;
-import com.intellij.psi.PsiElement;
-import com.intellij.psi.PsiFile;
-import com.intellij.psi.PsiWhiteSpace;
+import com.intellij.psi.*;
 import com.intellij.psi.codeStyle.CodeStyleManager;
 import com.intellij.psi.codeStyle.CodeStyleSettingsManager;
 import com.intellij.psi.util.PsiTreeUtil;
@@ -286,7 +283,7 @@ public class PyImportOptimizer implements ImportOptimizer {
       final PyImportStatementBase lastImport = ContainerUtil.getLastItem(myImportBlock);
       assert lastImport != null;
       addImportsAfter(lastImport);
-      myFile.deleteChildRange(firstElementToRemove, PyPsiUtils.getNextNonWhitespaceSibling(lastImport).getPrevSibling());
+      deleteRangeThroughDocument(firstElementToRemove, PyPsiUtils.getNextNonWhitespaceSibling(lastImport).getPrevSibling());
     }
 
     private void addImportsAfter(@NotNull PsiElement anchor) {
@@ -331,5 +328,11 @@ public class PyImportOptimizer implements ImportOptimizer {
 
       myFile.addRangeAfter(reformattedFile.getFirstChild(), reformattedFile.getLastChild(), anchor);
     }
+
+    private static void deleteRangeThroughDocument(@NotNull PsiElement first, @NotNull PsiElement last) {
+      PyUtil.updateDocumentUnblockedAndCommitted(first, document -> {
+        document.deleteString(first.getTextRange().getStartOffset(), last.getTextRange().getEndOffset());
+      });
+    }
   }
 }
diff --git a/python/src/com/jetbrains/python/psi/PyUtil.java b/python/src/com/jetbrains/python/psi/PyUtil.java
index 7239f01cc7f3..d7fac1ed3fc4 100644
--- a/python/src/com/jetbrains/python/psi/PyUtil.java
+++ b/python/src/com/jetbrains/python/psi/PyUtil.java
@@ -910,6 +910,25 @@ public class PyUtil {
     return as(PyPsiUtils.getPrevNonWhitespaceSibling(statementList), PsiComment.class);
   }
 
+  /**
+   * Retrieve the document from {@link PsiDocumentManager} using the anchor PSI element and pass it to the consumer function
+   * first releasing it from pending PSI modifications it with {@link PsiDocumentManager#doPostponedOperationsAndUnblockDocument(Document)}
+   * and then committing in try/finally block, so that subsequent operations over the PSI can be performed.
+   */
+  public static void updateDocumentUnblockedAndCommitted(@NotNull PsiElement anchor, @NotNull Consumer<Document> consumer) {
+    final PsiDocumentManager manager = PsiDocumentManager.getInstance(anchor.getProject());
+    final Document document = manager.getDocument(anchor.getContainingFile());
+    if (document != null) {
+      manager.doPostponedOperationsAndUnblockDocument(document);
+      try {
+        consumer.consume(document);
+      }
+      finally {
+        manager.commitDocument(document);
+      }
+    }
+  }
+
   public static class KnownDecoratorProviderHolder {
     public static PyKnownDecoratorProvider[] KNOWN_DECORATOR_PROVIDERS = Extensions.getExtensions(PyKnownDecoratorProvider.EP_NAME);
 
diff --git a/python/testData/optimizeImports/blankLineBetweenDocstringAndFirstImportPreserved.after.py b/python/testData/optimizeImports/blankLineBetweenDocstringAndFirstImportPreserved.after.py
new file mode 100644
index 000000000000..64cebe733bee
--- /dev/null
+++ b/python/testData/optimizeImports/blankLineBetweenDocstringAndFirstImportPreserved.after.py
@@ -0,0 +1,9 @@
+# pylint: disable=missing-docstring, invalid-name
+
+"""2016 - Day 1 Puzzle Part 2 tests."""
+
+import sys
+
+from mod import solve, in_between, Point
+
+print(solve, in_between, Point, sys)
\ No newline at end of file
diff --git a/python/testData/optimizeImports/blankLineBetweenDocstringAndFirstImportPreserved.py b/python/testData/optimizeImports/blankLineBetweenDocstringAndFirstImportPreserved.py
new file mode 100644
index 000000000000..f748d726e656
--- /dev/null
+++ b/python/testData/optimizeImports/blankLineBetweenDocstringAndFirstImportPreserved.py
@@ -0,0 +1,10 @@
+# pylint: disable=missing-docstring, invalid-name
+
+"""2016 - Day 1 Puzzle Part 2 tests."""
+
+import sys
+
+
+from mod import solve, in_between, Point
+
+print(solve, in_between, Point, sys)
\ No newline at end of file
diff --git a/python/testData/optimizeImports/blankLineBetweenEncodingDeclarationAndFirstImportPreserved.after.py b/python/testData/optimizeImports/blankLineBetweenEncodingDeclarationAndFirstImportPreserved.after.py
new file mode 100644
index 000000000000..1e0b9391bd2f
--- /dev/null
+++ b/python/testData/optimizeImports/blankLineBetweenEncodingDeclarationAndFirstImportPreserved.after.py
@@ -0,0 +1,6 @@
+# -*- coding: utf-8
+from __future__ import unicode_literals, absolute_import
+
+import os
+
+os.listdir('.')
diff --git a/python/testData/optimizeImports/blankLineBetweenEncodingDeclarationAndFirstImportPreserved.py b/python/testData/optimizeImports/blankLineBetweenEncodingDeclarationAndFirstImportPreserved.py
new file mode 100644
index 000000000000..1e0b9391bd2f
--- /dev/null
+++ b/python/testData/optimizeImports/blankLineBetweenEncodingDeclarationAndFirstImportPreserved.py
@@ -0,0 +1,6 @@
+# -*- coding: utf-8
+from __future__ import unicode_literals, absolute_import
+
+import os
+
+os.listdir('.')
diff --git a/python/testSrc/com/jetbrains/python/PyOptimizeImportsTest.java b/python/testSrc/com/jetbrains/python/PyOptimizeImportsTest.java
index e8a3caa99b37..b198c7ea09da 100644
--- a/python/testSrc/com/jetbrains/python/PyOptimizeImportsTest.java
+++ b/python/testSrc/com/jetbrains/python/PyOptimizeImportsTest.java
@@ -88,11 +88,7 @@ public class PyOptimizeImportsTest extends PyTestCase {
 
   // PY-16351
   public void testNoExtraBlankLineAfterImportBlock() {
-    final String testName = getTestName(true);
-    myFixture.copyDirectoryToProject(testName, "");
-    myFixture.configureByFile("main.py");
-    OptimizeImportsAction.actionPerformedImpl(DataManager.getInstance().getDataContext(myFixture.getEditor().getContentComponent()));
-    myFixture.checkResultByFile(testName + "/main.after.py");
+    doMultiFileTest();
   }
 
   // PY-18521
@@ -298,6 +294,24 @@ public class PyOptimizeImportsTest extends PyTestCase {
     doTest();
   }
 
+  // PY-23578
+  public void testBlankLineBetweenDocstringAndFirstImportPreserved() {
+    doTest();
+  }
+
+  // PY-23636
+  public void testBlankLineBetweenEncodingDeclarationAndFirstImportPreserved() {
+    doTest();
+  }
+
+  private void doMultiFileTest() {
+    final String testName = getTestName(true);
+    myFixture.copyDirectoryToProject(testName, "");
+    myFixture.configureByFile("main.py");
+    OptimizeImportsAction.actionPerformedImpl(DataManager.getInstance().getDataContext(myFixture.getEditor().getContentComponent()));
+    myFixture.checkResultByFile(testName + "/main.after.py");
+  }
+
   private void doTest() {
     myFixture.configureByFile(getTestName(true) + ".py");
     OptimizeImportsAction.actionPerformedImpl(DataManager.getInstance().getDataContext(myFixture.getEditor().getContentComponent()));