diff --git a/src/cmd/cos_gpu_installer/internal/commands/install.go b/src/cmd/cos_gpu_installer/internal/commands/install.go
index eb5c8c3..9cbea92 100644
--- a/src/cmd/cos_gpu_installer/internal/commands/install.go
+++ b/src/cmd/cos_gpu_installer/internal/commands/install.go
@@ -150,7 +150,7 @@
 			"Those are the public COS artifacts buckets.")
 	f.StringVar(&c.gcsDownloadPrefix, "gcs-download-prefix", "",
 		"The GCS path prefix when downloading COS artifacts."+
-			"If not set then the COS version build number (e.g. 13310.1041.38) will be used.")
+			"If not set then the COS build number and board (e.g. 13310.1041.38/lakitu) will be used.")
 	f.StringVar(&c.nvidiaInstallerURL, "nvidia-installer-url", "",
 		"A URL to an nvidia-installer to use for driver installation. This flag is mutually exclusive with `-version`. "+
 			"This flag must be used with `-allow-unsigned-driver`. This flag is only for debugging and testing.")
diff --git a/src/cmd/cos_gpu_installer/internal/commands/list.go b/src/cmd/cos_gpu_installer/internal/commands/list.go
index 4aed9ff..c4649ba 100644
--- a/src/cmd/cos_gpu_installer/internal/commands/list.go
+++ b/src/cmd/cos_gpu_installer/internal/commands/list.go
@@ -38,7 +38,7 @@
 			"For example, the default value is 'cos-tools' which is the public COS artifacts bucket.")
 	f.StringVar(&c.gcsDownloadPrefix, "gcs-download-prefix", "",
 		"The GCS path prefix when downloading COS artifacts."+
-			"If not set then the COS version build number (e.g. 13310.1041.38) will be used.")
+			"If not set then the COS build number and board (e.g. 13310.1041.38/lakitu) will be used.")
 	f.BoolVar(&c.debug, "debug", false,
 		"Enable debug mode.")
 }
diff --git a/src/pkg/cos/artifacts.go b/src/pkg/cos/artifacts.go
index 16592ac..f46defd 100644
--- a/src/pkg/cos/artifacts.go
+++ b/src/pkg/cos/artifacts.go
@@ -75,9 +75,9 @@
 			}
 		}
 	}
-	// Use build number as the default GCS download prefix.
+	// Use {build number}/{board} as the default GCS download prefix.
 	if prefix == "" {
-		prefix = e.BuildNumber()
+		prefix = path.Join(e.BuildNumber(), e.Board())
 	}
 	return &GCSDownloader{e, bucket, prefix}
 }
diff --git a/src/pkg/cos/env_reader.go b/src/pkg/cos/env_reader.go
index 44fa948..e0d819f 100644
--- a/src/pkg/cos/env_reader.go
+++ b/src/pkg/cos/env_reader.go
@@ -59,6 +59,9 @@
 // ReleaseTrack returns the COS release track.
 func (c *EnvReader) ReleaseTrack() string { return c.lsbRelease[releaseTrack] }
 
+// Board returns the COS board name. Retrieved from /etc/lsb-release.
+func (c *EnvReader) Board() string { return c.lsbRelease["CHROMEOS_RELEASE_BOARD"] }
+
 // BuildNumber returns COS build number.
 func (c *EnvReader) BuildNumber() string { return c.osRelease[buildID] }