diff --git a/ipv4/helper.go b/ipv4/helper.go
index 25e7568..b494a2c 100644
--- a/ipv4/helper.go
+++ b/ipv4/helper.go
@@ -32,7 +32,7 @@
 // See golang.org/issue/30899.
 func adjustFreeBSD32(m *socket.Message) {
 	// FreeBSD 12.0-RELEASE is affected by https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=236737
-	if freebsdVersion >= 1200086 && freebsdVersion < 1201000 {
+	if 1200086 <= freebsdVersion && freebsdVersion < 1201000 {
 		l := (m.NN + 4 - 1) &^ (4 - 1)
 		if m.NN < l && l <= len(m.OOB) {
 			m.NN = l