diff --git a/phrasebook/ch04/zero_initialization/main.go b/phrasebook/ch04/zero_initialization/main.go
new file mode 100644
index 0000000..4b6e962
--- /dev/null
+++ b/phrasebook/ch04/zero_initialization/main.go
@@ -0,0 +1,27 @@
+package main
+
+import (
+	"fmt"
+	"os"
+)
+
+type Logger struct {
+	out *os.File
+}
+
+func (l Logger) Log(s string) {
+	out := l.out
+	if out == nil {
+		out = os.Stderr
+	}
+	fmt.Fprintf(out, "%s [%d]: %s\n", os.Args[0],
+		os.Getpid(), s)
+}
+func (l *Logger) SetOutput(out *os.File) {
+	l.out = out
+}
+
+func main() {
+	l := Logger{}
+	l.Log("test")
+}