diff --git a/sample/memfd.cpp b/sample/memfd.cpp
index 1066c55..2b6d08b 100644
--- a/sample/memfd.cpp
+++ b/sample/memfd.cpp
@@ -1,6 +1,6 @@
 /*
 	a sample to use MmapAllocator with an user-defined name
-	cat /proc/`psidof ./memfd`/maps
+	cat /proc/`pidof ./memfd`/maps
 
 7fca70b44000-7fca70b4a000 rw-p 00000000 00:00 0
 7fca70b67000-7fca70b68000 rwxs 00000000 00:05 19960170                   /memfd:xyz (deleted)