diff --git a/src/modules/module_21600.c b/src/modules/module_21600.c
index 09d8f64e7..4a0e5445c 100644
--- a/src/modules/module_21600.c
+++ b/src/modules/module_21600.c
@@ -15,7 +15,7 @@ static const u32   DGST_POS0      = 0;
 static const u32   DGST_POS1      = 1;
 static const u32   DGST_POS2      = 2;
 static const u32   DGST_POS3      = 3;
-static const u32   DGST_SIZE      = DGST_SIZE_8_2;
+static const u32   DGST_SIZE      = DGST_SIZE_8_8;
 static const u32   HASH_CATEGORY  = HASH_CATEGORY_FRAMEWORK;
 static const char *HASH_NAME      = "Web2py pbkdf2-sha512";
 static const u64   KERN_TYPE      = 21600;