diff --git a/CHANGELOG.adoc b/CHANGELOG.adoc
index 3bd7b3b3afbc602db10f16f2c579e6eba028cd3c..65d1263a0a7ac2663ee5c31efd3cc006f4b2affc 100644
--- a/CHANGELOG.adoc
+++ b/CHANGELOG.adoc
@@ -4,6 +4,12 @@
 This document provides a summary of all notable changes to Antora Assembler by release.
 For a detailed view of what's changed, refer to the {url-repo}/commits[commit history] of this project.
 
+== Unreleased
+
+=== Fixed
+
+* don't unset doctype attribute in args passed to converter command (#98)
+
 == 1.0.0-beta.2 (2025-06-09)
 
 _No changes since previous release._
diff --git a/packages/assembler/lib/produce-assembly-files.js b/packages/assembler/lib/produce-assembly-files.js
index 96d9246f89516d383bd78faa9374ed43603ec3fb..94d347e5f0e469cb8a51cf1318b2c35a0342679a 100644
--- a/packages/assembler/lib/produce-assembly-files.js
+++ b/packages/assembler/lib/produce-assembly-files.js
@@ -87,7 +87,6 @@ function produceAssemblyFiles (loadAsciiDoc, contentCatalog, assemblerConfig, re
         accum.push(assemblyFile)
         return true
       }, false)
-      mergedAsciiDocAttributes.doctype = assemblyModel.doctype
       sourceHighlighter
         ? (mergedAsciiDocAttributes['source-highlighter'] = sourceHighlighter)
         : delete mergedAsciiDocAttributes['source-highlighter']
diff --git a/packages/assembler/test/assemble-content-test.js b/packages/assembler/test/assemble-content-test.js
index afc2bcf350c7531cf242792b3f22ff69add9ee7a..040cba4345b4fc07a972b07caed6d0baf520f396 100644
--- a/packages/assembler/test/assemble-content-test.js
+++ b/packages/assembler/test/assemble-content-test.js
@@ -266,15 +266,17 @@ describe('assembleContent()', () => {
     const playbook = { dir: ospath.join(FIXTURES_DIR, 'project-with-command') }
     const { contentCatalog, assemblerConfig: configSource } = await loadScenario(scenario, __dirname)
     Object.assign(configSource.build, { command: './convert-to-pdf', mkdirs: true, publish: false })
+    let actualConvertAttributes
     const convert = (doc, convertAttributes, buildConfig) => {
       const { cwd, command } = buildConfig
-      const outfile = convertAttributes.outfile
+      const outfile = (actualConvertAttributes = convertAttributes).outfile
       const args = convertAttributes.toArgs('-a', command).concat('-o', outfile, '-')
       const opts = { parse: true, cwd, stdin: doc.contents, stdout: 'print', stderr: 'print' }
       return runCommand(command, args, opts).then(() => fs.createReadStream(outfile))
     }
     const converter = { convert, extname: '.pdf', mediaType: 'application/pdf' }
     const actual = await assembleContent(playbook, contentCatalog, converter, { configSource })
+    assertx.doesNotHaveProperty(actualConvertAttributes, 'doctype') // TODO make a separate test for this assertion
     assert.equal(actual.length, 1)
     const actualContents = actual[0].contents
     assertx.instanceOf(actualContents, Readable)
diff --git a/packages/assembler/test/produce-assembly-files-test.js b/packages/assembler/test/produce-assembly-files-test.js
index 97bfcb7199c4245f0f977b8938eb14d9ebf23c6d..fce89eb91649988db0b3a44cf2c00a64d665a657 100644
--- a/packages/assembler/test/produce-assembly-files-test.js
+++ b/packages/assembler/test/produce-assembly-files-test.js
@@ -200,7 +200,8 @@ describe('produceAssemblyFiles()', () => {
     const { loadAsciiDoc, contentCatalog, assemblerConfig } = await loadScenario('override-doctype', __dirname)
     const assemblyFiles = await produceAssemblyFiles(loadAsciiDoc, contentCatalog, assemblerConfig)
     assert.equal(assemblyFiles.length, 1)
-    assert.equal(assemblyFiles[0].asciidoc.attributes.doctype, 'article')
+    assert.doesNotMatch(assemblyFiles[0].contents.toString(), /:doctype:/)
+    assertx.doesNotHaveProperty(assemblyFiles[0].asciidoc.attributes, 'doctype')
   })
 
   it('should allow doctype to be overridden using assembly model', async () => {
@@ -209,8 +210,8 @@ describe('produceAssemblyFiles()', () => {
     assemblerConfig.assembly.doctype = 'article'
     const assemblyFiles = await produceAssemblyFiles(loadAsciiDoc, contentCatalog, assemblerConfig)
     assert.equal(assemblyFiles.length, 1)
-    assert.doesNotMatch(assemblyFiles[0].contents.toString(), /:doctype: book/)
-    assert.equal(assemblyFiles[0].asciidoc.attributes.doctype, 'article')
+    assert.doesNotMatch(assemblyFiles[0].contents.toString(), /^:doctype: book$/m)
+    assertx.doesNotHaveProperty(assemblyFiles[0].asciidoc.attributes, 'doctype')
   })
 
   it('should process name section of manpage', async () => {