diff --git a/ucl/inst_test.go b/ucl/inst_test.go
index 06c60a0..7a9149a 100644
--- a/ucl/inst_test.go
+++ b/ucl/inst_test.go
@@ -174,6 +174,20 @@ func TestInst_Eval_WithSubEnv(t *testing.T) {
 				want1: "hello",
 				want2: "world",
 			},
+			{
+				descr: "exporting procs 1",
+				eval1: `export say_hello { "hello" } ; hook { say_hello }`,
+				eval2: `hook { say_hello }`,
+				want1: "hello",
+				want2: "hello",
+			},
+			{
+				descr: "exporting procs 2",
+				eval1: `$a = "hello" ; export say_hello { $a = "world"; $a } ; hook { say_hello }`,
+				eval2: `$a = "other" ; hook { say_hello }`,
+				want1: "world",
+				want2: "world",
+			},
 		}
 
 		for _, tt := range tests {
@@ -193,6 +207,19 @@ func TestInst_Eval_WithSubEnv(t *testing.T) {
 
 					return nil, nil
 				})
+				inst.SetBuiltin("export", func(ctx context.Context, args ucl.CallArgs) (any, error) {
+					var (
+						name     string
+						hookProc ucl.Invokable
+					)
+
+					if err := args.Bind(&name, &hookProc); err != nil {
+						return nil, err
+					}
+					inst.SetBuiltinInvokable(name, hookProc)
+
+					return nil, nil
+				})
 
 				res, err := inst.Eval(ctx, strings.NewReader(tt.eval1), ucl.WithSubEnv())
 				assert.NoError(t, err)
diff --git a/ucl/userbuiltin.go b/ucl/userbuiltin.go
index 7058b0e..83d72d6 100644
--- a/ucl/userbuiltin.go
+++ b/ucl/userbuiltin.go
@@ -81,6 +81,10 @@ func (inst *Inst) SetBuiltin(name string, fn BuiltinHandler) {
 	inst.rootEC.addCmd(name, userBuiltin{fn: fn})
 }
 
+func (inst *Inst) SetBuiltinInvokable(name string, fn Invokable) {
+	inst.rootEC.addCmd(name, fn.inv)
+}
+
 type userBuiltin struct {
 	fn func(ctx context.Context, args CallArgs) (any, error)
 }