diff --git a/4-empty-interface-in-go/Makefile b/4-empty-interface-in-go/Makefile
new file mode 100644
index 0000000..d476aff
--- /dev/null
+++ b/4-empty-interface-in-go/Makefile
@@ -0,0 +1,2 @@
+all:
+	go run main.go
diff --git a/4-empty-interface-in-go/main.go b/4-empty-interface-in-go/main.go
new file mode 100644
index 0000000..1c86a2d
--- /dev/null
+++ b/4-empty-interface-in-go/main.go
@@ -0,0 +1,18 @@
+package main
+
+import "fmt"
+
+func main() {
+    var i interface{}
+    describe(i)
+
+    i = 42
+    describe(i)
+
+    i = "hello"
+    describe(i)
+}
+
+func describe(i interface{}) {
+    fmt.Printf("(%v, %T)\n", i, i)
+}