diff --git a/flock_unix.go b/flock_unix.go
index ad30aa3..e64dfae 100644
--- a/flock_unix.go
+++ b/flock_unix.go
@@ -3,7 +3,7 @@
 // Use of this source code is governed by the BSD 3-Clause
 // license that can be found in the LICENSE file.
 
-//go:build !aix && !solaris && !windows
+//go:build !aix && (!solaris || illumos) && !windows
 
 package flock
 
diff --git a/flock_unix_variants.go b/flock_unix_variants.go
index 4774b01..ad5c4a5 100644
--- a/flock_unix_variants.go
+++ b/flock_unix_variants.go
@@ -15,7 +15,7 @@
 // This code is adapted from the Go package:
 // cmd/go/internal/lockedfile/internal/filelock
 
-//go:build aix || solaris
+//go:build aix || (solaris && !illumos)
 
 package flock