diff --git a/unix/zsysctl_openbsd_386.go b/unix/zsysctl_openbsd_386.go
index 37dcc74c..102f1ab4 100644
--- a/unix/zsysctl_openbsd_386.go
+++ b/unix/zsysctl_openbsd_386.go
@@ -1,4 +1,4 @@
-// mksysctl_openbsd.pl
+// go run mksysctl_openbsd.go
 // Code generated by the command above; DO NOT EDIT.
 
 // +build 386,openbsd
@@ -30,6 +30,7 @@ var sysctlMib = []mibentry{
 	{"hw.model", []_C_int{6, 2}},
 	{"hw.ncpu", []_C_int{6, 3}},
 	{"hw.ncpufound", []_C_int{6, 21}},
+	{"hw.ncpuonline", []_C_int{6, 25}},
 	{"hw.pagesize", []_C_int{6, 7}},
 	{"hw.physmem", []_C_int{6, 19}},
 	{"hw.product", []_C_int{6, 15}},
diff --git a/unix/zsysctl_openbsd_amd64.go b/unix/zsysctl_openbsd_amd64.go
index fe6caa6e..4866fced 100644
--- a/unix/zsysctl_openbsd_amd64.go
+++ b/unix/zsysctl_openbsd_amd64.go
@@ -31,6 +31,7 @@ var sysctlMib = []mibentry{
 	{"hw.model", []_C_int{6, 2}},
 	{"hw.ncpu", []_C_int{6, 3}},
 	{"hw.ncpufound", []_C_int{6, 21}},
+	{"hw.ncpuonline", []_C_int{6, 25}},
 	{"hw.pagesize", []_C_int{6, 7}},
 	{"hw.perfpolicy", []_C_int{6, 23}},
 	{"hw.physmem", []_C_int{6, 19}},
diff --git a/unix/zsysctl_openbsd_arm.go b/unix/zsysctl_openbsd_arm.go
index 6eb8c0b0..d3801eb2 100644
--- a/unix/zsysctl_openbsd_arm.go
+++ b/unix/zsysctl_openbsd_arm.go
@@ -30,6 +30,7 @@ var sysctlMib = []mibentry{
 	{"hw.model", []_C_int{6, 2}},
 	{"hw.ncpu", []_C_int{6, 3}},
 	{"hw.ncpufound", []_C_int{6, 21}},
+	{"hw.ncpuonline", []_C_int{6, 25}},
 	{"hw.pagesize", []_C_int{6, 7}},
 	{"hw.physmem", []_C_int{6, 19}},
 	{"hw.product", []_C_int{6, 15}},