diff --git a/src/main/java/org/mindrot/BCrypt.java b/src/main/java/org/mindrot/BCrypt.java
index 188193f..f3f23dd 100644
--- a/src/main/java/org/mindrot/BCrypt.java
+++ b/src/main/java/org/mindrot/BCrypt.java
@@ -662,7 +662,7 @@ public static String hashpw(String password, String salt) {
 			off = 3;
 		else {
 			minor = salt.charAt(2);
-			if (minor != 'a' || salt.charAt(3) != '$')
+			if (minor != 'y' || salt.charAt(3) != '$')
 				throw new IllegalArgumentException ("Invalid salt revision");
 			off = 4;
 		}