diff --git a/scans/README.md b/scans/README.md
index 359beea..4deeef1 100644
--- a/scans/README.md
+++ b/scans/README.md
@@ -28,7 +28,7 @@ Details of the files:
 * sop.s pages 62-63  of 01-s1.pdf
 * maksys.s: page 64  of 01-s1.pdf
 * trysys.s: page 65  of 01-s1.pdf
-* scope.v: pages 3-18 of 03-scope.pdf
+* scope.cas: pages 3-18 of 03-scope.pdf
 * cas.s: pages 1-8 of 04-cas.pdf
 * cas.x: pages 9-17 of 04-cas.pdf
 * adm.s: pages 2-11  of 05-1-4.pdf
diff --git a/scans/scope.v b/scans/scope.cas
similarity index 100%
rename from scans/scope.v
rename to scans/scope.cas