diff --git a/compiler/channel.go b/compiler/channel.go
index 6e2d4319..a036fbf4 100644
--- a/compiler/channel.go
+++ b/compiler/channel.go
@@ -79,8 +79,7 @@ func (b *builder) createChanRecv(unop *ssa.UnOp) llvm.Value {
 }
 
 // createChanClose closes the given channel.
-func (b *builder) createChanClose(param ssa.Value) {
-	ch := b.getValue(param)
+func (b *builder) createChanClose(ch llvm.Value) {
 	b.createRuntimeCall("chanClose", []llvm.Value{ch}, "")
 }
 
diff --git a/compiler/compiler.go b/compiler/compiler.go
index d9a5ed4e..d31d2077 100644
--- a/compiler/compiler.go
+++ b/compiler/compiler.go
@@ -130,7 +130,9 @@ func newBuilder(c *compilerContext, irbuilder llvm.Builder, f *ir.Function) *bui
 }
 
 type deferBuiltin struct {
-	funcName string
+	callName string
+	pos      token.Pos
+	argTypes []types.Type
 	callback int
 }
 
@@ -1196,11 +1198,11 @@ func (b *builder) createInstruction(instr ssa.Instruction) {
 
 // createBuiltin lowers a builtin Go function (append, close, delete, etc.) to
 // LLVM IR. It uses runtime calls for some builtins.
-func (b *builder) createBuiltin(args []ssa.Value, callName string, pos token.Pos) (llvm.Value, error) {
+func (b *builder) createBuiltin(argTypes []types.Type, argValues []llvm.Value, callName string, pos token.Pos) (llvm.Value, error) {
 	switch callName {
 	case "append":
-		src := b.getValue(args[0])
-		elems := b.getValue(args[1])
+		src := argValues[0]
+		elems := argValues[1]
 		srcBuf := b.CreateExtractValue(src, 0, "append.srcBuf")
 		srcPtr := b.CreateBitCast(srcBuf, b.i8ptrType, "append.srcPtr")
 		srcLen := b.CreateExtractValue(src, 1, "append.srcLen")
@@ -1221,9 +1223,9 @@ func (b *builder) createBuiltin(args []ssa.Value, callName string, pos token.Pos
 		newSlice = b.CreateInsertValue(newSlice, newCap, 2, "")
 		return newSlice, nil
 	case "cap":
-		value := b.getValue(args[0])
+		value := argValues[0]
 		var llvmCap llvm.Value
-		switch args[0].Type().(type) {
+		switch argTypes[0].(type) {
 		case *types.Chan:
 			llvmCap = b.createRuntimeCall("chanCap", []llvm.Value{value}, "cap")
 		case *types.Slice:
@@ -1236,12 +1238,12 @@ func (b *builder) createBuiltin(args []ssa.Value, callName string, pos token.Pos
 		}
 		return llvmCap, nil
 	case "close":
-		b.createChanClose(args[0])
+		b.createChanClose(argValues[0])
 		return llvm.Value{}, nil
 	case "complex":
-		r := b.getValue(args[0])
-		i := b.getValue(args[1])
-		t := args[0].Type().Underlying().(*types.Basic)
+		r := argValues[0]
+		i := argValues[1]
+		t := argTypes[0].Underlying().(*types.Basic)
 		var cplx llvm.Value
 		switch t.Kind() {
 		case types.Float32:
@@ -1255,8 +1257,8 @@ func (b *builder) createBuiltin(args []ssa.Value, callName string, pos token.Pos
 		cplx = b.CreateInsertValue(cplx, i, 1, "")
 		return cplx, nil
 	case "copy":
-		dst := b.getValue(args[0])
-		src := b.getValue(args[1])
+		dst := argValues[0]
+		src := argValues[1]
 		dstLen := b.CreateExtractValue(dst, 1, "copy.dstLen")
 		srcLen := b.CreateExtractValue(src, 1, "copy.srcLen")
 		dstBuf := b.CreateExtractValue(dst, 0, "copy.dstArray")
@@ -1267,16 +1269,16 @@ func (b *builder) createBuiltin(args []ssa.Value, callName string, pos token.Pos
 		elemSize := llvm.ConstInt(b.uintptrType, b.targetData.TypeAllocSize(elemType), false)
 		return b.createRuntimeCall("sliceCopy", []llvm.Value{dstBuf, srcBuf, dstLen, srcLen, elemSize}, "copy.n"), nil
 	case "delete":
-		m := b.getValue(args[0])
-		key := b.getValue(args[1])
-		return llvm.Value{}, b.createMapDelete(args[1].Type(), m, key, pos)
+		m := argValues[0]
+		key := argValues[1]
+		return llvm.Value{}, b.createMapDelete(argTypes[1], m, key, pos)
 	case "imag":
-		cplx := b.getValue(args[0])
+		cplx := argValues[0]
 		return b.CreateExtractValue(cplx, 1, "imag"), nil
 	case "len":
-		value := b.getValue(args[0])
+		value := argValues[0]
 		var llvmLen llvm.Value
-		switch args[0].Type().Underlying().(type) {
+		switch argTypes[0].Underlying().(type) {
 		case *types.Basic, *types.Slice:
 			// string or slice
 			llvmLen = b.CreateExtractValue(value, 1, "len")
@@ -1292,12 +1294,11 @@ func (b *builder) createBuiltin(args []ssa.Value, callName string, pos token.Pos
 		}
 		return llvmLen, nil
 	case "print", "println":
-		for i, arg := range args {
+		for i, value := range argValues {
 			if i >= 1 && callName == "println" {
 				b.createRuntimeCall("printspace", nil, "")
 			}
-			value := b.getValue(arg)
-			typ := arg.Type().Underlying()
+			typ := argTypes[i].Underlying()
 			switch typ := typ.(type) {
 			case *types.Basic:
 				switch typ.Kind() {
@@ -1349,13 +1350,13 @@ func (b *builder) createBuiltin(args []ssa.Value, callName string, pos token.Pos
 		}
 		return llvm.Value{}, nil // print() or println() returns void
 	case "real":
-		cplx := b.getValue(args[0])
+		cplx := argValues[0]
 		return b.CreateExtractValue(cplx, 0, "real"), nil
 	case "recover":
 		return b.createRuntimeCall("_recover", nil, ""), nil
 	case "ssa:wrapnilchk":
 		// TODO: do an actual nil check?
-		return b.getValue(args[0]), nil
+		return argValues[0], nil
 	default:
 		return llvm.Value{}, b.makeError(pos, "todo: builtin: "+callName)
 	}
@@ -1432,7 +1433,13 @@ func (b *builder) createFunctionCall(instr *ssa.CallCommon) (llvm.Value, error)
 		exported = targetFunc.IsExported()
 	} else if call, ok := instr.Value.(*ssa.Builtin); ok {
 		// Builtin function (append, close, delete, etc.).)
-		return b.createBuiltin(instr.Args, call.Name(), instr.Pos())
+		var argTypes []types.Type
+		var argValues []llvm.Value
+		for _, arg := range instr.Args {
+			argTypes = append(argTypes, arg.Type())
+			argValues = append(argValues, b.getValue(arg))
+		}
+		return b.createBuiltin(argTypes, argValues, call.Name(), instr.Pos())
 	} else {
 		// Function pointer.
 		value := b.getValue(instr.Value)
diff --git a/compiler/defer.go b/compiler/defer.go
index db2bed32..eb35ab23 100644
--- a/compiler/defer.go
+++ b/compiler/defer.go
@@ -155,19 +155,19 @@ func (b *builder) createDefer(instr *ssa.Defer) {
 		valueTypes = append(valueTypes, context.Type())
 
 	} else if builtin, ok := instr.Call.Value.(*ssa.Builtin); ok {
-		var funcName string
-		switch builtin.Name() {
-		case "close":
-			funcName = "chanClose"
-		default:
-			b.addError(instr.Pos(), "todo: Implement defer for "+builtin.Name())
-			return
+		var argTypes []types.Type
+		var argValues []llvm.Value
+		for _, arg := range instr.Call.Args {
+			argTypes = append(argTypes, arg.Type())
+			argValues = append(argValues, b.getValue(arg))
 		}
 
 		if _, ok := b.deferBuiltinFuncs[instr.Call.Value]; !ok {
 			b.deferBuiltinFuncs[instr.Call.Value] = deferBuiltin{
-				funcName,
-				len(b.allDeferFuncs),
+				callName: builtin.Name(),
+				pos:      builtin.Pos(),
+				argTypes: argTypes,
+				callback: len(b.allDeferFuncs),
 			}
 			b.allDeferFuncs = append(b.allDeferFuncs, instr.Call.Value)
 		}
@@ -176,10 +176,9 @@ func (b *builder) createDefer(instr *ssa.Defer) {
 		// Collect all values to be put in the struct (starting with
 		// runtime._defer fields).
 		values = []llvm.Value{callback, next}
-		for _, param := range instr.Call.Args {
-			llvmParam := b.getValue(param)
-			values = append(values, llvmParam)
-			valueTypes = append(valueTypes, llvmParam.Type())
+		for _, param := range argValues {
+			values = append(values, param)
+			valueTypes = append(valueTypes, param.Type())
 		}
 
 	} else {
@@ -426,15 +425,18 @@ func (b *builder) createRunDefers() {
 			deferFramePtr := b.CreateBitCast(deferData, llvm.PointerType(deferFrameType, 0), "deferFrame")
 
 			// Extract the params from the struct.
-			var forwardParams []llvm.Value
+			var argValues []llvm.Value
 			zero := llvm.ConstInt(b.ctx.Int32Type(), 0, false)
 			for i := 0; i < params.Len(); i++ {
 				gep := b.CreateInBoundsGEP(deferFramePtr, []llvm.Value{zero, llvm.ConstInt(b.ctx.Int32Type(), uint64(i+2), false)}, "gep")
 				forwardParam := b.CreateLoad(gep, "param")
-				forwardParams = append(forwardParams, forwardParam)
+				argValues = append(argValues, forwardParam)
 			}
 
-			b.createRuntimeCall(db.funcName, forwardParams, "")
+			_, err := b.createBuiltin(db.argTypes, argValues, db.callName, db.pos)
+			if err != nil {
+				b.diagnostics = append(b.diagnostics, err)
+			}
 		default:
 			panic("unknown deferred function type")
 		}
diff --git a/testdata/calls.go b/testdata/calls.go
index 9f6ba69f..d1c80dd0 100644
--- a/testdata/calls.go
+++ b/testdata/calls.go
@@ -72,7 +72,8 @@ func main() {
 	regression1033()
 
 	//Test deferred builtins
-	testDeferBuiltin()
+	testDeferBuiltinClose()
+	testDeferBuiltinDelete()
 }
 
 func runFunc(f func(int), arg int) {
@@ -121,13 +122,30 @@ func testMultiFuncVar() {
 	defer f(1)
 }
 
-func testDeferBuiltin() {
+func testDeferBuiltinClose() {
 	i := make(chan int)
-	defer close(i)
+	func() {
+		defer close(i)
+	}()
+	if n, ok := <-i; n != 0 || ok {
+		println("expected to read 0 from closed channel")
+	}
+}
+
+func testDeferBuiltinDelete() {
+	m := map[int]int{3: 30, 5: 50}
+	func() {
+		defer delete(m, 3)
+		if m[3] != 30 {
+			println("expected m[3] to be 30")
+		}
+	}()
+	if m[3] != 0 {
+		println("expected m[3] to be 0")
+	}
 }
 
 type dumb struct {
-
 }
 
 func (*dumb) Value(key interface{}) interface{} {
@@ -144,17 +162,17 @@ func exportedDefer() {
 }
 
 func deferFunc() (int, func(int)) {
-	return 0, func(i int){println("...extracted defer func ", i)}
+	return 0, func(i int) { println("...extracted defer func ", i) }
 }
 
 func multiFuncDefer() func(int) {
 	i := 0
 
 	if i > 0 {
-		return func(i int){println("Should not have gotten here. i = ", i)}
+		return func(i int) { println("Should not have gotten here. i = ", i) }
 	}
 
-	return func(i int){println("Called the correct function. i = ", i)}
+	return func(i int) { println("Called the correct function. i = ", i) }
 }
 
 func testBound(f func() string) {