diff --git a/lib/libsys/thr_kill.2 b/lib/libsys/thr_kill.2
index 3252de13ed8..63a6e40ef6f 100644
--- a/lib/libsys/thr_kill.2
+++ b/lib/libsys/thr_kill.2
@@ -26,7 +26,7 @@
 .\" SUCH DAMAGE.
 .\"
 .Dd May 5, 2020
-.Dt THR_kill 2
+.Dt THR_KILL 2
 .Os
 .Sh NAME
 .Nm thr_kill