diff --git a/book.toml b/book.toml
index f4ffa64..9ab628f 100644
--- a/book.toml
+++ b/book.toml
@@ -3,7 +3,7 @@ authors = ["Ali Gottschall", "João Pereira"]
 language = "en"
 multilingual = false
 src = "src"
-title = "Practical Program Verification in Go with Gobra"
+title = "Practical Program Verification in Go with Gobra (alpha)"
 
 [output.html]
 theme = "theme"