diff --git a/book/source/a-artifacts.md b/book/source/a-artifacts.md
index cb01bde..721d23d 100644
--- a/book/source/a-artifacts.md
+++ b/book/source/a-artifacts.md
@@ -2,7 +2,7 @@
 
 ## Alice's private key
 
-```
+```text
 -----BEGIN PGP PRIVATE KEY BLOCK-----
 Comment: AAA1 8CBB 2546 85C5 8358 3205 63FD 37B6  7F33 00F9 FB0E C457 378C D29F 1026 98B3
 Comment: <alice@example.org>