diff --git a/crypto/signature_cgo.go b/crypto/signature_cgo.go
index 665a20429a..ad5bd7c247 100644
--- a/crypto/signature_cgo.go
+++ b/crypto/signature_cgo.go
@@ -14,7 +14,7 @@
 // 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/>.
 
-// +build !nacl,!js,!nocgo
+// +build !nacl,!js,cgo
 
 package crypto
 
diff --git a/crypto/signature_nocgo.go b/crypto/signature_nocgo.go
index f636b23772..908b04e4f8 100644
--- a/crypto/signature_nocgo.go
+++ b/crypto/signature_nocgo.go
@@ -14,7 +14,7 @@
 // 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/>.
 
-// +build nacl js nocgo
+// +build nacl js !cgo
 
 package crypto