diff --git a/internal/lsp/command/command_gen.go b/internal/lsp/command/command_gen.go
index 5980f353ca..d3dbfd5125 100644
--- a/internal/lsp/command/command_gen.go
+++ b/internal/lsp/command/command_gen.go
@@ -2,6 +2,10 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// Don't include this file during code generation, or it will break the build
+// if existing interface methods have been modified.
+// +build !generate
+
 package command
 
 // Code generated by generate.go. DO NOT EDIT.
diff --git a/internal/lsp/command/generate/generate.go b/internal/lsp/command/generate/generate.go
index d206e22cec..d31b437489 100644
--- a/internal/lsp/command/generate/generate.go
+++ b/internal/lsp/command/generate/generate.go
@@ -20,6 +20,10 @@ const src = `// Copyright 2021 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// Don't include this file during code generation, or it will break the build
+// if existing interface methods have been modified.
+// +build !generate
+
 package command
 
 // Code generated by generate.go. DO NOT EDIT.
diff --git a/internal/lsp/command/interface.go b/internal/lsp/command/interface.go
index cbfa1c57f5..4f068fa777 100644
--- a/internal/lsp/command/interface.go
+++ b/internal/lsp/command/interface.go
@@ -12,7 +12,7 @@
 // also provided by this package, via code generation.
 package command
 
-//go:generate go run generate.go
+//go:generate go run -tags=generate generate.go
 
 import "golang.org/x/tools/internal/lsp/protocol"