diff --git a/book/source/09-verification.md b/book/source/09-verification.md
index 4d495ab..9820afc 100644
--- a/book/source/09-verification.md
+++ b/book/source/09-verification.md
@@ -183,7 +183,7 @@ Preferences are sourced from signatures on different components, depending on ho
 ```
 
 If the user wants to write an email as "Bob", it should consider the signature on "Bob", so SHA256 should be used as hash algorithm.
-If instead the user wants to write as "Bobby", the impementation should inspect the self-certification on "Bobby" instead.
+If instead the user wants to write as "Bobby", the implementation should inspect the self-certification on "Bobby" instead.
 However, since this signature does not carry any hash algorithm preferences subpacket, the implementation must fall back to the direct key signature instead.
 The same is true, if the certificate is used without any User ID as sender.