diff --git a/cmd/govulncheck/internal/govulncheck/cache.go b/cmd/govulncheck/internal/govulncheck/cache.go
index 0948837..404c356 100644
--- a/cmd/govulncheck/internal/govulncheck/cache.go
+++ b/cmd/govulncheck/internal/govulncheck/cache.go
@@ -2,6 +2,9 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build go1.18
+// +build go1.18
+
 // Package govulncheck supports the govulncheck command.
 package govulncheck
 
diff --git a/cmd/govulncheck/internal/govulncheck/cache_test.go b/cmd/govulncheck/internal/govulncheck/cache_test.go
index 0917ae8..5a25c78 100644
--- a/cmd/govulncheck/internal/govulncheck/cache_test.go
+++ b/cmd/govulncheck/internal/govulncheck/cache_test.go
@@ -2,6 +2,9 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build go1.18
+// +build go1.18
+
 package govulncheck
 
 import (
diff --git a/cmd/govulncheck/internal/govulncheck/source.go b/cmd/govulncheck/internal/govulncheck/source.go
index 9f91665..752a831 100644
--- a/cmd/govulncheck/internal/govulncheck/source.go
+++ b/cmd/govulncheck/internal/govulncheck/source.go
@@ -2,6 +2,9 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build go1.18
+// +build go1.18
+
 package govulncheck
 
 import (
diff --git a/cmd/govulncheck/internal/govulncheck/util.go b/cmd/govulncheck/internal/govulncheck/util.go
index 6699236..baa2d96 100644
--- a/cmd/govulncheck/internal/govulncheck/util.go
+++ b/cmd/govulncheck/internal/govulncheck/util.go
@@ -2,6 +2,9 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build go1.18
+// +build go1.18
+
 package govulncheck
 
 import (
diff --git a/cmd/govulncheck/internal/govulncheck/util_test.go b/cmd/govulncheck/internal/govulncheck/util_test.go
index 67e7772..3288cd8 100644
--- a/cmd/govulncheck/internal/govulncheck/util_test.go
+++ b/cmd/govulncheck/internal/govulncheck/util_test.go
@@ -2,6 +2,9 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build go1.18
+// +build go1.18
+
 package govulncheck
 
 import (