diff --git a/README.md b/README.md
index 528abe9..8bd90e9 100644
--- a/README.md
+++ b/README.md
@@ -44,5 +44,5 @@ For pinned bootstrap usage, generate a `channels.scm` that combines upstream
 Guix with this repository's current commit.
 
 The deployment scripts default to the checked-in base-channel lock at
-`pins/base-channels.scm`.  Refresh that lock intentionally with
+`pins/base-channels.sexpr`.  Refresh that lock intentionally with
 `../guix-deploy/scripts/update-base-channels-pin`.
diff --git a/pins/base-channels.scm b/pins/base-channels.sexpr
similarity index 100%
rename from pins/base-channels.scm
rename to pins/base-channels.sexpr