diff --git a/CHANGELOG.adoc b/CHANGELOG.adoc
index 8a134c57559854df323af19f8d7a222fd639476c..bfb0a4f51f435e1dbbb0422b15493bbd844f115e 100644
--- a/CHANGELOG.adoc
+++ b/CHANGELOG.adoc
@@ -36,6 +36,8 @@ For a detailed view of what's changed, refer to the {url-repo}/commits[commit hi
 === Changed
 
 * preserve block attributes (except for style and shorthands) on doctitle when adding page to assembly (#99)
+* support assembly-navtitle override for doctitle when root level is 1 (#119)
+
 
 === Fixed
 
diff --git a/packages/assembler/lib/produce-assembly-file.js b/packages/assembler/lib/produce-assembly-file.js
index bc4dd4c11bb35912672fdc598b04ae40fbce6ad7..6c4e6019385f69de3e21887119f199b9c74c5578 100644
--- a/packages/assembler/lib/produce-assembly-file.js
+++ b/packages/assembler/lib/produce-assembly-file.js
@@ -147,7 +147,15 @@ function mergeAsciiDoc (
     if (doc.hasAttribute('assembly-navtitle')) {
       navtitleAsciiDoc = doc.getAttribute('assembly-navtitle')
       navtitlePlain = sanitize((navtitle = doc.$apply_reftext_subs(navtitleAsciiDoc)))
-      if (buffer.inBody == null) buffer.navtitle = navtitle
+      if (buffer.inBody == null) {
+        buffer.navtitle = navtitle
+        // Q do we need to assert !level here?
+        if (assemblyModel.rootLevel) {
+          let doctitle = navtitleAsciiDoc
+          if (navtitlePlain !== componentVersion.title) doctitle = `${componentVersion.title}: ${doctitle}`
+          buffer[0] = `= ${doctitle}`
+        }
+      }
     }
     if (atDocumentRoot) {
       const authors = doc.getAuthors()
diff --git a/packages/assembler/test/produce-assembly-files-test.js b/packages/assembler/test/produce-assembly-files-test.js
index 4d220442c33ee4f1a392dae4b83c029fe17a3762..7d019a86ecf4abf65dd87d24b9bf42968dfbdd49 100644
--- a/packages/assembler/test/produce-assembly-files-test.js
+++ b/packages/assembler/test/produce-assembly-files-test.js
@@ -306,6 +306,10 @@ describe('produceAssemblyFiles()', () => {
     assert.equal(assemblyFiles[0].src.stem, 'the-page')
   })
 
+  it('should use value of assembly-navtitle to override doctitle when root level is 1', async () => {
+    await runScenario('root-level-1-assembly-navtitle', __dirname)
+  })
+
   it('should process content in AsciiDoc table cell', async () => {
     await runScenario('process-asciidoc-table-cell', __dirname)
   })
diff --git a/packages/assembler/test/scenarios/root-level-1-assembly-navtitle/data.yml b/packages/assembler/test/scenarios/root-level-1-assembly-navtitle/data.yml
new file mode 100644
index 0000000000000000000000000000000000000000..a5896d0073a15c09128e3e88fe5cc550be9d6bd4
--- /dev/null
+++ b/packages/assembler/test/scenarios/root-level-1-assembly-navtitle/data.yml
@@ -0,0 +1,23 @@
+name: the-component
+version: '1.0'
+title: The Component
+navigation:
+  items:
+  - content: xref:page-a.adoc[]
+  - content: xref:page-b.adoc[]
+files:
+- relative: page-a.adoc
+  contents: |-
+    = Page A
+    :assembly-navtitle: A
+
+    contents
+- relative: page-b.adoc
+  contents: |-
+    = Page B
+    :assembly-navtitle: B
+
+    contents
+assembler:
+  assembly:
+    rootLevel: 1
diff --git a/packages/assembler/test/scenarios/root-level-1-assembly-navtitle/expects/a.adoc b/packages/assembler/test/scenarios/root-level-1-assembly-navtitle/expects/a.adoc
new file mode 100644
index 0000000000000000000000000000000000000000..b6b100a76a0e3b25d9fc4874d0ca5ae201720132
--- /dev/null
+++ b/packages/assembler/test/scenarios/root-level-1-assembly-navtitle/expects/a.adoc
@@ -0,0 +1,21 @@
+[#page-a]
+= The Component: A
+:revnumber: 1.0
+:doctype: book
+:underscore: _
+:page-component-name: the-component
+:page-component-version: 1.0
+:page-version: {page-component-version}
+:page-component-display-version: 1.0
+:page-component-title: The Component
+
+:docname: page-a
+:page-module: ROOT
+:page-relative-src-path: page-a.adoc
+:page-origin-url: https://github.com/acme/the-component
+:page-origin-start-path:
+:page-origin-refname: v1.0
+:page-origin-reftype: branch
+:page-origin-refhash: a00000000000000000000000000000000000000z
+
+contents
diff --git a/packages/assembler/test/scenarios/root-level-1-assembly-navtitle/expects/b.adoc b/packages/assembler/test/scenarios/root-level-1-assembly-navtitle/expects/b.adoc
new file mode 100644
index 0000000000000000000000000000000000000000..936bebd0c198643a0c2e924daaaecd962b243fc4
--- /dev/null
+++ b/packages/assembler/test/scenarios/root-level-1-assembly-navtitle/expects/b.adoc
@@ -0,0 +1,21 @@
+[#page-b]
+= The Component: B
+:revnumber: 1.0
+:doctype: book
+:underscore: _
+:page-component-name: the-component
+:page-component-version: 1.0
+:page-version: {page-component-version}
+:page-component-display-version: 1.0
+:page-component-title: The Component
+
+:docname: page-b
+:page-module: ROOT
+:page-relative-src-path: page-b.adoc
+:page-origin-url: https://github.com/acme/the-component
+:page-origin-start-path:
+:page-origin-refname: v1.0
+:page-origin-reftype: branch
+:page-origin-refhash: a00000000000000000000000000000000000000z
+
+contents