diff --git a/windows/mkerrors.go b/windows/mkerrors.go
index cbf123ef..a204e6ca 100644
--- a/windows/mkerrors.go
+++ b/windows/mkerrors.go
@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// +build generate
+
 package windows
 
 //go:generate ./mkerrors.bash zerrors_windows.go
diff --git a/windows/mksyscall.go b/windows/mksyscall.go
index fb7db0ef..62770572 100644
--- a/windows/mksyscall.go
+++ b/windows/mksyscall.go
@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// +build generate
+
 package windows
 
 //go:generate go run $GOROOT/src/syscall/mksyscall_windows.go -output zsyscall_windows.go eventlog.go service.go syscall_windows.go security_windows.go
diff --git a/windows/registry/mksyscall.go b/windows/registry/mksyscall.go
index 0ac95ffe..cf843ce2 100644
--- a/windows/registry/mksyscall.go
+++ b/windows/registry/mksyscall.go
@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// +build generate
+
 package registry
 
 //go:generate go run $GOROOT/src/syscall/mksyscall_windows.go -output zsyscall_windows.go syscall.go