diff --git a/ethutil/script_unix.go b/ethutil/script_unix.go
index bd087e7e0..37e5bf91b 100644
--- a/ethutil/script_unix.go
+++ b/ethutil/script_unix.go
@@ -1,3 +1,5 @@
+// +build !windows
+
 package ethutil
 
 import (
diff --git a/ethutil/script_windows.go b/ethutil/script_windows.go
index 4f94c6448..ef239cd51 100644
--- a/ethutil/script_windows.go
+++ b/ethutil/script_windows.go
@@ -1,3 +1,5 @@
+// +build windows
+
 package ethutil
 
 import (