diff --git a/src/basic/math_consts/b9d6.const_INV_SQR_2.s b/src/basic/math_consts/b9d6.const_INV_SQR_2.s
index a538c7bc..8427adaf 100644
--- a/src/basic/math_consts/b9d6.const_INV_SQR_2.s
+++ b/src/basic/math_consts/b9d6.const_INV_SQR_2.s
@@ -3,8 +3,13 @@
 ;; #LAYOUT# *   BASIC_0 #TAKE
 ;; #LAYOUT# *   *       #IGNORE
 
+; This file is under the MIT license, it contains code released by Microsoft Corporation.
+; See LICENSE for more information.
+
+; Math package - 1 / sqr(2)
+;
+; This is verified to be identical to the original Microsoft implementation where it was named SQRHLF.
 ;
-; Math package - a constant, for documentation see:
 ; - https://www.c64-wiki.com/wiki/BASIC-ROM
 ;
 
diff --git a/tools/similarity.c b/tools/similarity.c
index 26579973..13ff9927 100644
--- a/tools/similarity.c
+++ b/tools/similarity.c
@@ -27,7 +27,7 @@ unsigned short microsoft_basic_chunks[NUM_CHUNKS * 2] = {
     0xB391, 0xB39D,
     0xB3A2, 0xB3A5,
     0xB849, 0xB97D,
-    0xB983, 0xB9D5, 
+    0xB983, 0xB9DA, 
     0xB9EA, 0xBCF2,
     0xBD7E, 0xBD90,
     0xBDB3, 0xBDC1,