diff --git a/doc/src/sgml/pgcrypto.sgml b/doc/src/sgml/pgcrypto.sgml
index 3e64099fe8dc0e6d3356ab5330f4ccfda980d773..b82ff665a6f33ea488725d5f0a7a08e1ecccb5bc 100644
--- a/doc/src/sgml/pgcrypto.sgml
+++ b/doc/src/sgml/pgcrypto.sgml
@@ -63,7 +63,7 @@ $$ LANGUAGE SQL STRICT IMMUTABLE;
 
 <synopsis>
 hmac(data text, key text, type text) returns bytea
-hmac(data bytea, key text, type text) returns bytea
+hmac(data bytea, key bytea, type text) returns bytea
 </synopsis>
 
    <para>