diff --git a/core/shared/src/main/scala/laika/internal/nav/SectionBuilder.scala b/core/shared/src/main/scala/laika/internal/nav/SectionBuilder.scala
index a63bb1ba1..180dff67d 100644
--- a/core/shared/src/main/scala/laika/internal/nav/SectionBuilder.scala
+++ b/core/shared/src/main/scala/laika/internal/nav/SectionBuilder.scala
@@ -63,21 +63,28 @@ private[laika] object SectionBuilder extends RewriteRulesBuilder {
 
     def buildSections(document: RootElement): RootElement = {
 
+      def flatten(blocks: Seq[Block]): Seq[Block] = blocks.flatMap {
+        case seq: BlockSequence if seq.options.styles.isEmpty && !seq.hasId => flatten(seq.content)
+        case b: Block                                                       => Seq(b)
+      }
+
+      val flattenedDocument = flatten(document.content)
+
       val docPosition = if (autonumberConfig.documents) position else TreePosition.root
 
       val (titleSection, rest) =
-        if (!extractTitle) (Nil, document.content)
+        if (!extractTitle) (Nil, flattenedDocument)
         else {
 
-          val title = document.content.collectFirst { case h: Header =>
+          val title = flattenedDocument.collectFirst { case h: Header =>
             if (autonumberConfig.documents)
               Title(addNumber(h.content, docPosition), h.options + Style.title)
             else Title(h.content, h.options + Style.title)
           }
 
-          title.fold((document.content, Seq.empty[Block])) { titleBlock =>
+          title.fold((flattenedDocument, Seq.empty[Block])) { titleBlock =>
             val (preface, rest) =
-              document.content.splitAt(document.content.indexWhere(_.isInstanceOf[Header]))
+              flattenedDocument.splitAt(flattenedDocument.indexWhere(_.isInstanceOf[Header]))
             (preface :+ titleBlock, rest.tail)
           }
         }
diff --git a/core/shared/src/test/scala/laika/directive/std/StandardDirectiveSpec.scala b/core/shared/src/test/scala/laika/directive/std/StandardDirectiveSpec.scala
index 1260804a6..b41cdccf4 100644
--- a/core/shared/src/test/scala/laika/directive/std/StandardDirectiveSpec.scala
+++ b/core/shared/src/test/scala/laika/directive/std/StandardDirectiveSpec.scala
@@ -132,7 +132,7 @@ class StandardDirectiveSpec extends FunSuite
                   |@:todo(FIXME LATER)
                   |
                   |bb""".stripMargin
-    run(input, p("aa"), BlockSequence(Nil), p("bb"))
+    run(input, p("aa"), p("bb"))
   }
 
   test("todo directive as span") {
diff --git a/core/shared/src/test/scala/laika/internal/rst/std/StandardBlockDirectivesSpec.scala b/core/shared/src/test/scala/laika/internal/rst/std/StandardBlockDirectivesSpec.scala
index 2d46f2f0c..0cb84e1d4 100644
--- a/core/shared/src/test/scala/laika/internal/rst/std/StandardBlockDirectivesSpec.scala
+++ b/core/shared/src/test/scala/laika/internal/rst/std/StandardBlockDirectivesSpec.scala
@@ -112,7 +112,7 @@ class StandardBlockDirectivesSpec extends FunSuite with ParagraphCompanionShortc
                   | 1st Para
                   |
                   | 2nd Para""".stripMargin
-    run(input, BlockSequence(simplePars))
+    run(input, simplePars *)
   }
 
   test("container - sequence of two paragraphs with two custom styles") {