diff --git a/consts.php b/consts.php
index 63d3a1c..5ac8585 100644
--- a/consts.php
+++ b/consts.php
@@ -23,6 +23,37 @@
     'recipe-blog',
 ];
 
+// list of modules that are required in either:
+// - silverstripe/installer
+// - silverstripe/recipe-cms
+// - silverstripe/recipe-core
+const INSTALLER_MODULES = [
+    // installer
+    'recipe-plugin',
+    'vendor-plugin',
+    'recipe-cms',
+    'silverstripe-simple',
+    'silverstripe-login-forms',
+    // recipe-cms
+    'recipe-core',
+    'silverstripe-admin',
+    'silverstripe-asset-admin',
+    'silverstripe-campaign-admin',
+    'silverstripe-versioned-admin',
+    'silverstripe-cms',
+    'silverstripe-errorpage',
+    'silverstripe-reports',
+    'silverstripe-siteconfig',
+    'silverstripe-versioned',
+    'silverstripe-graphql',
+    'silverstripe-session-manager',
+    // recipe-core
+    'silverstripe-assets',
+    'silverstripe-config',
+    'silverstripe-framework',
+    'silverstripe-mimevalidator',
+];
+
 // use hardcoded.php to bulk update update this after creating a .cow.pat.json
 // for multiple versions, use an array e.g. silverstripe-mymodule => ['2.3', '2.4']
 const INSTALLER_TO_REPO_MINOR_VERSIONS = [
diff --git a/job_creator.php b/job_creator.php
index 686c550..77154ab 100644
--- a/job_creator.php
+++ b/job_creator.php
@@ -132,10 +132,24 @@ public function getInstallerVersion(
 
     public function createJob(int $phpIndex, array $opts): array
     {
+        $isInstallerModule = in_array($this->repoName, INSTALLER_MODULES);
+        $isPreferLoweset = strpos($opts['composer_args'] ?? '', '--prefer-lowest') !== false;
+        $installerVersion = $this->installerVersion;
+        $cmsMajor = BranchLogic::getCmsMajor($this->repoData, $this->branch, $this->getComposerJsonContent());
+        if ($cmsMajor >= 5 && !$isInstallerModule && $isPreferLoweset && $installerVersion) {
+            // --prefer-lowest jobs should use the lowest installer version for non-installer modules
+            // gha-ci will increment the installer version higher if composer is unable to install
+            // and try installing again
+            //
+            // Was going to use something like 5.2.x-dev, install 5.0.x-dev instead
+            $installerVersion = preg_replace('#^([0-9])\.[0-9]\.x-dev$#', '$1.0.x-dev', $installerVersion);
+            // Was going to use something like 5.x-dev, install 5.0.x-dev instaed
+            $installerVersion = preg_replace('#^([0-9])\.x-dev$#', '$1.0.x-dev', $installerVersion);
+        }
         $default = [
             # ensure there's a default value for all possible return keys
             # this allows us to use `if [[ "${{ matrix.key }}" == "true" ]]; then` in gha-ci/ci.yml
-            'installer_version' => $this->installerVersion,
+            'installer_version' => $installerVersion,
             'php' => $this->getPhpVersion($phpIndex),
             'parent_branch' => $this->parentBranch,
             'db' => DB_MYSQL_57,
diff --git a/tests/JobCreatorTest.php b/tests/JobCreatorTest.php
index 844e054..9d1de4c 100644
--- a/tests/JobCreatorTest.php
+++ b/tests/JobCreatorTest.php
@@ -5,6 +5,49 @@
 
 class JobCreatorTest extends TestCase
 {
+    public function provideCreateJobPreferLowest(): array
+    {
+        return [
+            'installer-module cms 4' => [
+                'branch' => '4',
+                'ghrepo' => 'silverstripe/silverstripe-framework',
+                'expected' => '4.x-dev',
+            ],
+            'non-installer-module cms 4' => [
+                'branch' => '4',
+                'ghrepo' => 'dnadesign/silverstripe-elemental',
+                'expected' => '4.x-dev',
+            ],
+            'installer-module cms 5' => [
+                'branch' => '5',
+                'ghrepo' => 'silverstripe/silverstripe-framework',
+                'expected' => '5.x-dev',
+            ],
+            'non-installer-module cms 5' => [
+                'branch' => '5',
+                'ghrepo' => 'dnadesign/silverstripe-elemental',
+                'expected' => '5.0.x-dev',
+            ],
+        ];
+    }
+
+    /**
+     * @dataProvider provideCreateJobPreferLowest
+     */
+    public function testCreateJobPreferLowest(string $branch, string $ghrepo, string $expected): void
+    {
+        $installerVersionProperty = new ReflectionProperty(JobCreator::class, 'installerVersion');
+        $installerVersionProperty->setAccessible(true);
+        $creator = new JobCreator();
+        $installerVersionProperty->setValue($creator, "$branch.x-dev");
+        $creator->githubRepository = $ghrepo;
+        $creator->repoName = explode('/', $ghrepo)[1];
+        $creator->branch = $branch;
+        $creator->parseRepositoryMetadata();
+        $actual = $creator->createJob(0, ['composer_args' => '--prefer-lowest'])['installer_version'];
+        $this->assertSame($expected, $actual);
+    }
+
     /**
      * @dataProvider provideCreateJob
      */
@@ -962,7 +1005,7 @@ public function testGetInstallerVersionFromComposer(
             $creator = new JobCreator();
             $creator->composerJsonPath = '__composer.json';
             $json = json_decode($creator->createJson($yml));
-            $this->assertSame($expected, $json->include[0]->installer_version);
+            $this->assertSame($expected, $json->include[1]->installer_version);
         } finally {
             unlink('__composer.json');
             unlink('__installer_branches.json');
diff --git a/tests/bootstrap.php b/tests/bootstrap.php
index 6832380..b946eb9 100644
--- a/tests/bootstrap.php
+++ b/tests/bootstrap.php
@@ -1,4 +1,10 @@
 <?php
+$autoloadPath = __DIR__ . '/../vendor/autoload.php';
+if (!file_exists($autoloadPath)) {
+    throw new RuntimeException('Run composer install first');
+}
+require_once $autoloadPath;
+
 // working directory will be root
 include 'consts.php';
 include 'job_creator.php';