diff --git a/global.go b/global.go
index 26f50a0..a345960 100644
--- a/global.go
+++ b/global.go
@@ -214,3 +214,18 @@ func (g *Global) setenv(ctx context.Context, w *gmnlisp.World, __key, __val gmnl
 
 	return gmnlisp.Null, os.Setenv(key, val)
 }
+
+func (g *Global) wait(ctx context.Context, w *gmnlisp.World, pidNode gmnlisp.Node) (gmnlisp.Node, error) {
+	pidInteger, err := gmnlisp.ExpectClass[gmnlisp.Integer](ctx, w, pidNode)
+	if err != nil {
+		return nil, err
+	}
+	pid := int(pidInteger)
+
+	process, err := os.FindProcess(pid)
+	if err != nil {
+		return gmnlisp.Null, nil
+	}
+	_, err = process.Wait()
+	return gmnlisp.Null, err
+}
diff --git a/main.go b/main.go
index 7254ffa..72cd26e 100644
--- a/main.go
+++ b/main.go
@@ -39,6 +39,7 @@ func mains(args []string) error {
 			gmnlisp.NewSymbol("expect"):  gmnlisp.SpecialF(g.expect),
 			gmnlisp.NewSymbol("getenv"):  gmnlisp.Function1(g.getenv),
 			gmnlisp.NewSymbol("setenv"):  gmnlisp.Function2(g.setenv),
+			gmnlisp.NewSymbol("wait"):    gmnlisp.Function1(g.wait),
 		})
 
 	if len(args) <= 0 {