diff --git a/cl/_testrt/intgen/out.ll b/cl/_testrt/intgen/out.ll
index dbf5271e..ab28bc81 100644
--- a/cl/_testrt/intgen/out.ll
+++ b/cl/_testrt/intgen/out.ll
@@ -22,11 +22,12 @@ _llgo_1:                                          ; preds = %_llgo_2, %_llgo_0
   br i1 %8, label %_llgo_2, label %_llgo_3
 
 _llgo_2:                                          ; preds = %_llgo_1
-  %9 = extractvalue { ptr, ptr } %1, 0
-  %10 = call i32 %9()
-  %11 = call ptr @"github.com/goplus/llgo/internal/runtime.SliceData"(%"github.com/goplus/llgo/internal/runtime.Slice" %4)
-  %12 = getelementptr inbounds i32, ptr %11, i64 %7
-  store i32 %10, ptr %12, align 4
+  %9 = extractvalue { ptr, ptr } %1, 1
+  %10 = extractvalue { ptr, ptr } %1, 0
+  %11 = call i32 %10(ptr %9)
+  %12 = call ptr @"github.com/goplus/llgo/internal/runtime.SliceData"(%"github.com/goplus/llgo/internal/runtime.Slice" %4)
+  %13 = getelementptr inbounds i32, ptr %12, i64 %7
+  store i32 %11, ptr %13, align 4
   br label %_llgo_1
 
 _llgo_3:                                          ; preds = %_llgo_1
@@ -54,7 +55,7 @@ _llgo_0:
   store i32 1, ptr %0, align 4
   %1 = alloca { ptr, ptr }, align 8
   %2 = getelementptr inbounds { ptr, ptr }, ptr %1, i32 0, i32 0
-  store ptr @rand, ptr %2, align 8
+  store ptr @__llgo_stub.rand, ptr %2, align 8
   %3 = getelementptr inbounds { ptr, ptr }, ptr %1, i32 0, i32 1
   store ptr null, ptr %3, align 8
   %4 = load { ptr, ptr }, ptr %1, align 8
@@ -118,6 +119,12 @@ declare void @"github.com/goplus/llgo/internal/runtime.init"()
 
 declare i32 @rand()
 
+define i32 @__llgo_stub.rand(ptr %0) {
+_llgo_0:
+  %1 = call i32 @rand()
+  ret i32 %1
+}
+
 declare i32 @printf(ptr, ...)
 
 define i32 @"main.main$1"({ ptr } %0) {
diff --git a/ssa/decl.go b/ssa/decl.go
index 7ac0e42e..53ad05e4 100644
--- a/ssa/decl.go
+++ b/ssa/decl.go
@@ -26,8 +26,9 @@ import (
 // -----------------------------------------------------------------------------
 
 const (
-	ClosureCtx = "__llgo_ctx"
-	NameValist = "__llgo_va_list"
+	ClosureCtx  = "__llgo_ctx"
+	ClosureStub = "__llgo_stub."
+	NameValist  = "__llgo_va_list"
 )
 
 func VArg() *types.Var {
diff --git a/ssa/expr.go b/ssa/expr.go
index 70e67402..f1f0153a 100644
--- a/ssa/expr.go
+++ b/ssa/expr.go
@@ -358,10 +358,7 @@ func (b Builder) UnOp(op token.Token, x Expr) Expr {
 func checkExpr(v Expr, t types.Type, b Builder) Expr {
 	if t, ok := t.(*types.Struct); ok && isClosure(t) {
 		if v.kind != vkClosure {
-			log.Panicln("checkExpr:", v.impl.Name())
-			prog := b.Prog
-			nilVal := prog.Null(prog.VoidPtr()).impl
-			return b.aggregateValue(prog.rawType(t), v.impl, nilVal)
+			return b.Func.Pkg.closureStub(b, t, v)
 		}
 	}
 	return v
diff --git a/ssa/package.go b/ssa/package.go
index a73651df..a0de6d0b 100644
--- a/ssa/package.go
+++ b/ssa/package.go
@@ -17,6 +17,7 @@
 package ssa
 
 import (
+	"go/token"
 	"go/types"
 	"log"
 
@@ -223,10 +224,11 @@ func (p Program) NewPackage(name, pkgPath string) Package {
 	mod := p.ctx.NewModule(pkgPath)
 	// TODO(xsw): Finalize may cause panic, so comment it.
 	// mod.Finalize()
-	fns := make(map[string]Function)
 	gbls := make(map[string]Global)
+	fns := make(map[string]Function)
+	stubs := make(map[string]Function)
 	p.needRuntime = false
-	return &aPackage{mod, fns, gbls, p}
+	return &aPackage{mod, gbls, fns, stubs, p}
 }
 
 // Void returns void type.
@@ -309,10 +311,11 @@ func (p Program) Float64() Type {
 // initializer) and "init#%d", the nth declared init function,
 // and unspecified other things too.
 type aPackage struct {
-	mod  llvm.Module
-	fns  map[string]Function
-	vars map[string]Global
-	Prog Program
+	mod   llvm.Module
+	vars  map[string]Global
+	fns   map[string]Function
+	stubs map[string]Function
+	Prog  Program
 }
 
 type Package = *aPackage
@@ -365,6 +368,30 @@ func (p Package) rtFunc(fnName string) Expr {
 	return p.NewFunc(name, sig, InGo).Expr
 }
 
+func (p Package) closureStub(b Builder, t *types.Struct, v Expr) Expr {
+	name := v.impl.Name()
+	prog := b.Prog
+	nilVal := prog.Null(prog.VoidPtr()).impl
+	if fn, ok := p.stubs[name]; ok {
+		v = fn.Expr
+	} else {
+		sig := v.raw.Type.(*types.Signature)
+		n := sig.Params().Len()
+		ctx := types.NewParam(token.NoPos, nil, ClosureCtx, types.Typ[types.UnsafePointer])
+		sig = FuncAddCtx(ctx, sig)
+		fn := p.NewFunc(ClosureStub+name, sig, InC)
+		args := make([]Expr, n)
+		for i := 0; i < n; i++ {
+			args[i] = fn.Param(i + 1)
+		}
+		b := fn.MakeBody(1)
+		b.Return(b.Call(v, args...))
+		p.stubs[name] = fn
+		v = fn.Expr
+	}
+	return b.aggregateValue(prog.rawType(t), v.impl, nilVal)
+}
+
 // FuncOf returns a function by name.
 func (p Package) FuncOf(name string) Function {
 	return p.fns[name]