diff --git a/examples/ch2-05-internal/cgo-gen-files/Makefile b/examples/ch2-05-internal/cgo-gen-files/Makefile
new file mode 100644
index 0000000..f9c683f
--- /dev/null
+++ b/examples/ch2-05-internal/cgo-gen-files/Makefile
@@ -0,0 +1,9 @@
+# Copyright © 2017 ChaiShushan <chaishushan{AT}gmail.com>.
+# License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+
+default: clean
+	# ignore nocgo_*.go files
+	go tool cgo main.go hello.go
+
+clean:
+	-rm -rf ./_obj
diff --git a/examples/ch2-05-internal/cgo-gen-files/hello.go b/examples/ch2-05-internal/cgo-gen-files/hello.go
new file mode 100644
index 0000000..ea79195
--- /dev/null
+++ b/examples/ch2-05-internal/cgo-gen-files/hello.go
@@ -0,0 +1,6 @@
+// Copyright © 2017 ChaiShushan <chaishushan{AT}gmail.com>.
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+
+package main
+
+import "C"
diff --git a/examples/ch2-05-internal/cgo-gen-files/main.go b/examples/ch2-05-internal/cgo-gen-files/main.go
new file mode 100644
index 0000000..2628a41
--- /dev/null
+++ b/examples/ch2-05-internal/cgo-gen-files/main.go
@@ -0,0 +1,8 @@
+// Copyright © 2017 ChaiShushan <chaishushan{AT}gmail.com>.
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+
+package main
+
+import "C"
+
+func main() {}
diff --git a/examples/ch2-05-internal/cgo-gen-files/nocgo_1.go b/examples/ch2-05-internal/cgo-gen-files/nocgo_1.go
new file mode 100644
index 0000000..171878b
--- /dev/null
+++ b/examples/ch2-05-internal/cgo-gen-files/nocgo_1.go
@@ -0,0 +1,4 @@
+// Copyright © 2017 ChaiShushan <chaishushan{AT}gmail.com>.
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+
+package main
diff --git a/examples/ch2-05-internal/cgo-gen-files/nocgo_x.go b/examples/ch2-05-internal/cgo-gen-files/nocgo_x.go
new file mode 100644
index 0000000..171878b
--- /dev/null
+++ b/examples/ch2-05-internal/cgo-gen-files/nocgo_x.go
@@ -0,0 +1,4 @@
+// Copyright © 2017 ChaiShushan <chaishushan{AT}gmail.com>.
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+
+package main