diff --git a/doc/arm/Bv9ARM-book.xml b/doc/arm/Bv9ARM-book.xml
index da6b76687d..bf4d176cd5 100644
--- a/doc/arm/Bv9ARM-book.xml
+++ b/doc/arm/Bv9ARM-book.xml
@@ -9890,7 +9890,7 @@ deny-answer-aliases { "example.net"; };
 		walled garden's authority DNS server.
 	      </listitem>
 	      <listitem>The <command>PASSTHRU</command> policy is specified
-		by a CNAME whose target is <command>rpz_passthru.</command>
+		by a CNAME whose target is <command>rpz-passthru.</command>
 		It causes the response to not be rewritten
 		and is most often used to "poke holes" in policies for
 		CIDR blocks.