diff --git a/filesystem/filesystem.go b/filesystem/filesystem.go
index e123f24..5dc7df6 100644
--- a/filesystem/filesystem.go
+++ b/filesystem/filesystem.go
@@ -69,10 +69,11 @@
 	// TODO(jiyong): allow apex_key to be specified here
 	Avb_private_key *string `android:"path"`
 
-	// Hash and signing algorithm for avbtool. Default is SHA256_RSA4096.
+	// Signing algorithm for avbtool. Default is SHA256_RSA4096.
 	Avb_algorithm *string
 
-	// Hash and signing algorithm for avbtool. Default is SHA256_RSA4096.
+	// Hash algorithm used for avbtool (for descriptors). This is passed as hash_algorithm to
+	// avbtool. Default used by avbtool is sha1.
 	Avb_hash_algorithm *string
 
 	// Name of the partition stored in vbmeta desc. Defaults to the name of this module.