diff --git a/tools/tools/pirtool/Makefile b/tools/tools/pirtool/Makefile
index a7999529c606..18e6bb84ef4a 100644
--- a/tools/tools/pirtool/Makefile
+++ b/tools/tools/pirtool/Makefile
@@ -2,6 +2,6 @@
 
 PROG=   pirtool
 SRCS=   pirtool.c
-NOMAN=
+NO_MAN=
 
 .include <bsd.prog.mk>