diff --git a/tests/fuzzers/bls12381/bls12381_fuzz.go b/tests/fuzzers/bls12381/bls12381_fuzz.go
index f04524f76a9f..9a5c566540f7 100644
--- a/tests/fuzzers/bls12381/bls12381_fuzz.go
+++ b/tests/fuzzers/bls12381/bls12381_fuzz.go
@@ -14,6 +14,9 @@
 // You should have received a copy of the GNU Lesser General Public License
 // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
 
+//go:build cgo
+// +build cgo
+
 package bls
 
 import (
diff --git a/tests/fuzzers/bls12381/bls12381_test.go b/tests/fuzzers/bls12381/bls12381_test.go
index 59e4db31d5d7..3e88979d1607 100644
--- a/tests/fuzzers/bls12381/bls12381_test.go
+++ b/tests/fuzzers/bls12381/bls12381_test.go
@@ -14,6 +14,9 @@
 // You should have received a copy of the GNU Lesser General Public License
 // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
 
+//go:build cgo
+// +build cgo
+
 package bls
 
 import "testing"