diff --git a/.gitignore b/.gitignore
index 85b0d4e..29c7b18 100644
--- a/.gitignore
+++ b/.gitignore
@@ -8,6 +8,7 @@ CLAUDE.md
 # Prebuilt libraries (committed to go branch only)
 /build-naive
 /lib/
-/include/
+/include/*
+!/include/dummy.go
 /cgo_*.go
 /lib_*_cgo.go
diff --git a/dummy.go b/dummy.go
new file mode 100644
index 0000000..b277ea1
--- /dev/null
+++ b/dummy.go
@@ -0,0 +1,12 @@
+//go:build dummy
+
+// This file exists purely to prevent the Go toolchain from stripping
+// away the C source directories and files when `go mod vendor` is used
+// to populate a `vendor/` directory of a project depending on this package.
+
+package cronet
+
+import (
+	// Prevent go tooling from stripping out the c source files.
+	_ "github.com/sagernet/cronet-go/include"
+)
diff --git a/include/dummy.go b/include/dummy.go
new file mode 100644
index 0000000..0f014ff
--- /dev/null
+++ b/include/dummy.go
@@ -0,0 +1,2 @@
+// Package include is a dummy package that prevents go tooling from stripping the C dependencies.
+package include