diff --git a/src/lib/json/generic.go b/src/lib/json/generic.go
index b57fcb12e22..08ae8dc29fb 100644
--- a/src/lib/json/generic.go
+++ b/src/lib/json/generic.go
@@ -75,7 +75,7 @@ func (j *_Array) Elem(i int) Json {
 	if i < 0 || i >= j.a.Len() {
 		return Null
 	}
-	return j.a.At(i)
+	return j.a.At(i).(Json)
 }
 func (j *_Array) String() string {
 	s := "[";
@@ -232,7 +232,7 @@ func (b *_JsonBuilder) Get() Json {
 	case b.ptr != nil:
 		return *b.ptr;
 	case b.a != nil:
-		return b.a.At(b.i);
+		return b.a.At(b.i).(Json);
 	case b.m != nil:
 		return b.m[b.k];
 	}
diff --git a/src/lib/json/struct.go b/src/lib/json/struct.go
index f37ee461efa..82e0a80a7bd 100644
--- a/src/lib/json/struct.go
+++ b/src/lib/json/struct.go
@@ -122,7 +122,7 @@ func (b *_StructBuilder) Array() {
 		pv := v.(reflect.PtrValue);
 		psubtype := pv.Type().(reflect.PtrType).Sub();
 		if pv.Get() == nil && psubtype.Kind() == reflect.ArrayKind {
-			av := reflect.NewSliceValue(psubtype, 0, 8);
+			av := reflect.NewSliceValue(psubtype.(reflect.ArrayType), 0, 8);
 			pv.SetSub(av);
 		}
 	}
@@ -148,7 +148,7 @@ func (b *_StructBuilder) Elem(i int) Builder {
 				for n <= i {
 					n *= 2
 				}
-				av1 := reflect.NewSliceValue(av.Type(), av.Len(), n);
+				av1 := reflect.NewSliceValue(av.Type().(reflect.ArrayType), av.Len(), n);
 				av1.CopyFrom(av, av.Len());
 				pv.SetSub(av1);
 				av = av1;
diff --git a/src/lib/reflect/all_test.go b/src/lib/reflect/all_test.go
index a840fc89287..f6428fdf384 100644
--- a/src/lib/reflect/all_test.go
+++ b/src/lib/reflect/all_test.go
@@ -270,7 +270,7 @@ func TestAll(tt *testing.T) {	// TODO(r): wrap up better
 	assert(typ.String(), "[]uint32");
 
 	t = reflect.ParseTypeString("", "[]int32");
-	v := reflect.NewSliceValue(t, 5, 10);
+	v := reflect.NewSliceValue(t.(ArrayType), 5, 10);
 	t1 := reflect.ParseTypeString("", "*[]int32");
 	v1 := reflect.NewInitValue(t1);
 	if v1 == nil { panic("V1 is nil"); }
@@ -308,7 +308,7 @@ func TestCopyArray(t *testing.T) {
 		}
 	}
 	for tocopy := 1; tocopy <= 7; tocopy++ {
-		vb.(PtrValue).Sub().(ArrayValue).CopyFrom(va.(PtrValue).Sub(), tocopy);
+		vb.(PtrValue).Sub().(ArrayValue).CopyFrom(va.(PtrValue).Sub().(ArrayValue), tocopy);
 		for i := 0; i < tocopy; i++ {
 			if a[i] != b[i] {
 				t.Errorf("1 tocopy=%d a[%d]=%d, b[%d]=%d",
diff --git a/src/lib/reflect/tostring.go b/src/lib/reflect/tostring.go
index d317e1a68f5..b2ccfdf4832 100644
--- a/src/lib/reflect/tostring.go
+++ b/src/lib/reflect/tostring.go
@@ -105,9 +105,9 @@ func TypeToString(typ Type, expand bool) string {
 		}
 		return str + TypeToString(c.Elem(), false);
 	case StructKind:
-		return "struct{" + typeFieldsToString(typ, ";") + "}";
+		return "struct{" + typeFieldsToString(typ.(StructType), ";") + "}";
 	case InterfaceKind:
-		return "interface{" + typeFieldsToString(typ, ";") + "}";
+		return "interface{" + typeFieldsToString(typ.(InterfaceType), ";") + "}";
 	case FuncKind:
 		f := typ.(FuncType);
 		str = "(" + typeFieldsToString(f.In(), ",") + ")";
diff --git a/src/lib/reflect/type.go b/src/lib/reflect/type.go
index b02ad32d7aa..d949f23f400 100644
--- a/src/lib/reflect/type.go
+++ b/src/lib/reflect/type.go
@@ -149,6 +149,12 @@ func (t *stubType) Get() Type {
 // -- Pointer
 
 type PtrType interface {
+	// TODO: Type;
+	Kind()	int;
+	Name()	string;
+	String()	string;
+	Size()	int;
+
 	Sub()	Type
 }
 
@@ -168,6 +174,12 @@ func (t *ptrTypeStruct) Sub() Type {
 // -- Array
 
 type ArrayType interface {
+	// TODO: Type;
+	Kind()	int;
+	Name()	string;
+	String()	string;
+	Size()	int;
+
 	IsSlice()	bool;
 	Len()	int;
 	Elem()	Type;
@@ -207,6 +219,12 @@ func (t *arrayTypeStruct) Elem() Type {
 // -- Map
 
 type MapType interface {
+	// TODO: Type;
+	Kind()	int;
+	Name()	string;
+	String()	string;
+	Size()	int;
+
 	Key()	Type;
 	Elem()	Type;
 }
@@ -232,6 +250,12 @@ func (t *mapTypeStruct) Elem() Type {
 // -- Chan
 
 type ChanType interface {
+	// TODO: Type;
+	Kind()	int;
+	Name()	string;
+	String()	string;
+	Size()	int;
+
 	Dir()	int;
 	Elem()	Type;
 }
@@ -263,6 +287,12 @@ func (t *chanTypeStruct) Elem() Type {
 // -- Struct
 
 type StructType interface {
+	// TODO: Type;
+	Kind()	int;
+	Name()	string;
+	String()	string;
+	Size()	int;
+
 	Field(int)	(name string, typ Type, tag string, offset int);
 	Len()	int;
 }
@@ -323,6 +353,12 @@ func (t *structTypeStruct) Len() int {
 // -- Interface
 
 type InterfaceType interface {
+	// TODO: Type;
+	Kind()	int;
+	Name()	string;
+	String()	string;
+	Size()	int;
+
 	Field(int)	(name string, typ Type, tag string, offset int);
 	Len()	int;
 }
@@ -349,6 +385,12 @@ var nilInterface = newInterfaceTypeStruct("nil", "", make([]structField, 0));
 // -- Func
 
 type FuncType interface {
+	// TODO: Type;
+	Kind()	int;
+	Name()	string;
+	String()	string;
+	Size()	int;
+
 	In()	StructType;
 	Out()	StructType;
 }
diff --git a/src/lib/reflect/value.go b/src/lib/reflect/value.go
index 8a2706e9745..6464d7e6d2d 100644
--- a/src/lib/reflect/value.go
+++ b/src/lib/reflect/value.go
@@ -66,9 +66,11 @@ type creatorFn func(typ Type, addr Addr) Value
 // -- Missing
 
 type MissingValue interface {
+	// TODO: Value;
 	Kind()	int;
 	Type()	Type;
 	Addr()	Addr;
+	Interface()	interface {};
 }
 
 type missingValueStruct struct {
@@ -82,10 +84,14 @@ func missingCreator(typ Type, addr Addr) Value {
 // -- Int
 
 type IntValue interface {
+	// TODO: Value;
 	Kind()	int;
+	Type()	Type;
+	Addr()	Addr;
+	Interface()	interface {};
+
 	Get()	int;
 	Set(int);
-	Type()	Type;
 }
 
 type intValueStruct struct {
@@ -107,10 +113,14 @@ func (v *intValueStruct) Set(i int) {
 // -- Int8
 
 type Int8Value interface {
+	// TODO: Value;
 	Kind()	int;
+	Type()	Type;
+	Addr()	Addr;
+	Interface()	interface {};
+
 	Get()	int8;
 	Set(int8);
-	Type()	Type;
 }
 
 type int8ValueStruct struct {
@@ -132,10 +142,14 @@ func (v *int8ValueStruct) Set(i int8) {
 // -- Int16
 
 type Int16Value interface {
+	// TODO: Value;
 	Kind()	int;
+	Type()	Type;
+	Addr()	Addr;
+	Interface()	interface {};
+
 	Get()	int16;
 	Set(int16);
-	Type()	Type;
 }
 
 type int16ValueStruct struct {
@@ -157,10 +171,14 @@ func (v *int16ValueStruct) Set(i int16) {
 // -- Int32
 
 type Int32Value interface {
+	// TODO: Value;
 	Kind()	int;
+	Type()	Type;
+	Addr()	Addr;
+	Interface()	interface {};
+
 	Get()	int32;
 	Set(int32);
-	Type()	Type;
 }
 
 type int32ValueStruct struct {
@@ -182,10 +200,14 @@ func (v *int32ValueStruct) Set(i int32) {
 // -- Int64
 
 type Int64Value interface {
+	// TODO: Value;
 	Kind()	int;
+	Type()	Type;
+	Addr()	Addr;
+	Interface()	interface {};
+
 	Get()	int64;
 	Set(int64);
-	Type()	Type;
 }
 
 type int64ValueStruct struct {
@@ -207,10 +229,14 @@ func (v *int64ValueStruct) Set(i int64) {
 // -- Uint
 
 type UintValue interface {
+	// TODO: Value;
 	Kind()	int;
+	Type()	Type;
+	Addr()	Addr;
+	Interface()	interface {};
+
 	Get()	uint;
 	Set(uint);
-	Type()	Type;
 }
 
 type uintValueStruct struct {
@@ -232,10 +258,14 @@ func (v *uintValueStruct) Set(i uint) {
 // -- Uint8
 
 type Uint8Value interface {
+	// TODO: Value;
 	Kind()	int;
+	Type()	Type;
+	Addr()	Addr;
+	Interface()	interface {};
+
 	Get()	uint8;
 	Set(uint8);
-	Type()	Type;
 }
 
 type uint8ValueStruct struct {
@@ -257,10 +287,14 @@ func (v *uint8ValueStruct) Set(i uint8) {
 // -- Uint16
 
 type Uint16Value interface {
+	// TODO: Value;
 	Kind()	int;
+	Type()	Type;
+	Addr()	Addr;
+	Interface()	interface {};
+
 	Get()	uint16;
 	Set(uint16);
-	Type()	Type;
 }
 
 type uint16ValueStruct struct {
@@ -282,10 +316,14 @@ func (v *uint16ValueStruct) Set(i uint16) {
 // -- Uint32
 
 type Uint32Value interface {
+	// TODO: Value;
 	Kind()	int;
+	Type()	Type;
+	Addr()	Addr;
+	Interface()	interface {};
+
 	Get()	uint32;
 	Set(uint32);
-	Type()	Type;
 }
 
 type uint32ValueStruct struct {
@@ -307,10 +345,14 @@ func (v *uint32ValueStruct) Set(i uint32) {
 // -- Uint64
 
 type Uint64Value interface {
+	// TODO: Value;
 	Kind()	int;
+	Type()	Type;
+	Addr()	Addr;
+	Interface()	interface {};
+
 	Get()	uint64;
 	Set(uint64);
-	Type()	Type;
 }
 
 type uint64ValueStruct struct {
@@ -332,10 +374,14 @@ func (v *uint64ValueStruct) Set(i uint64) {
 // -- Uintptr
 
 type UintptrValue interface {
+	// TODO: Value;
 	Kind()	int;
+	Type()	Type;
+	Addr()	Addr;
+	Interface()	interface {};
+
 	Get()	uintptr;
 	Set(uintptr);
-	Type()	Type;
 }
 
 type uintptrValueStruct struct {
@@ -357,10 +403,14 @@ func (v *uintptrValueStruct) Set(i uintptr) {
 // -- Float
 
 type FloatValue interface {
+	// TODO: Value;
 	Kind()	int;
+	Type()	Type;
+	Addr()	Addr;
+	Interface()	interface {};
+
 	Get()	float;
 	Set(float);
-	Type()	Type;
 }
 
 type floatValueStruct struct {
@@ -382,10 +432,14 @@ func (v *floatValueStruct) Set(f float) {
 // -- Float32
 
 type Float32Value interface {
+	// TODO: Value;
 	Kind()	int;
+	Type()	Type;
+	Addr()	Addr;
+	Interface()	interface {};
+
 	Get()	float32;
 	Set(float32);
-	Type()	Type;
 }
 
 type float32ValueStruct struct {
@@ -407,10 +461,14 @@ func (v *float32ValueStruct) Set(f float32) {
 // -- Float64
 
 type Float64Value interface {
+	// TODO: Value;
 	Kind()	int;
+	Type()	Type;
+	Addr()	Addr;
+	Interface()	interface {};
+
 	Get()	float64;
 	Set(float64);
-	Type()	Type;
 }
 
 type float64ValueStruct struct {
@@ -432,10 +490,14 @@ func (v *float64ValueStruct) Set(f float64) {
 // -- Float80
 
 type Float80Value interface {
+	// TODO: Value;
 	Kind()	int;
+	Type()	Type;
+	Addr()	Addr;
+	Interface()	interface {};
+
 	Get()	float80;
 	Set(float80);
-	Type()	Type;
 }
 
 type float80ValueStruct struct {
@@ -460,10 +522,14 @@ func (v *Float80ValueStruct) Set(f float80) {
 // -- String
 
 type StringValue interface {
+	// TODO: Value;
 	Kind()	int;
+	Type()	Type;
+	Addr()	Addr;
+	Interface()	interface {};
+
 	Get()	string;
 	Set(string);
-	Type()	Type;
 }
 
 type stringValueStruct struct {
@@ -485,10 +551,14 @@ func (v *stringValueStruct) Set(s string) {
 // -- Bool
 
 type BoolValue interface {
+	// TODO: Value;
 	Kind()	int;
+	Type()	Type;
+	Addr()	Addr;
+	Interface()	interface {};
+
 	Get()	bool;
 	Set(bool);
-	Type()	Type;
 }
 
 type boolValueStruct struct {
@@ -510,8 +580,12 @@ func (v *boolValueStruct) Set(b bool) {
 // -- Pointer
 
 type PtrValue interface {
+	// TODO: Value;
 	Kind()	int;
 	Type()	Type;
+	Addr()	Addr;
+	Interface()	interface {};
+
 	Sub()	Value;
 	Get()	Addr;
 	SetSub(Value);
@@ -547,8 +621,12 @@ func ptrCreator(typ Type, addr Addr) Value {
 // Slices and arrays are represented by the same interface.
 
 type ArrayValue interface {
+	// TODO: Value;
 	Kind()	int;
 	Type()	Type;
+	Addr()	Addr;
+	Interface()	interface {};
+
 	IsSlice()	bool;
 	Len()	int;
 	Cap() int;
@@ -681,8 +759,12 @@ func arrayCreator(typ Type, addr Addr) Value {
 // -- Map	TODO: finish and test
 
 type MapValue interface {
+	// TODO: Value;
 	Kind()	int;
 	Type()	Type;
+	Addr()	Addr;
+	Interface()	interface {};
+
 	Len()	int;
 	Elem(key Value)	Value;
 }
@@ -707,8 +789,11 @@ func (v *mapValueStruct) Elem(key Value) Value {
 // -- Chan
 
 type ChanValue interface {
+	// TODO: Value;
 	Kind()	int;
 	Type()	Type;
+	Addr()	Addr;
+	Interface()	interface {};
 }
 
 type chanValueStruct struct {
@@ -722,8 +807,12 @@ func chanCreator(typ Type, addr Addr) Value {
 // -- Struct
 
 type StructValue interface {
+	// TODO: Value;
 	Kind()	int;
 	Type()	Type;
+	Addr()	Addr;
+	Interface()	interface {};
+
 	Len()	int;
 	Field(i int)	Value;
 }
@@ -757,8 +846,12 @@ func structCreator(typ Type, addr Addr) Value {
 // -- Interface
 
 type InterfaceValue interface {
+	// TODO: Value;
 	Kind()	int;
 	Type()	Type;
+	Addr()	Addr;
+	Interface()	interface {};
+
 	Get()	interface {};
 }
 
@@ -777,8 +870,11 @@ func interfaceCreator(typ Type, addr Addr) Value {
 // -- Func
 
 type FuncValue interface {
+	// TODO: Value;
 	Kind()	int;
 	Type()	Type;
+	Addr()	Addr;
+	Interface()	interface {};
 }
 
 type funcValueStruct struct {
@@ -860,7 +956,7 @@ func NewSliceValue(typ ArrayType, len, cap int) ArrayValue {
 	array.len = uint32(len);
 	array.cap = uint32(cap);
 
-	return newValueAddr(typ, Addr(array));
+	return newValueAddr(typ, Addr(array)).(ArrayValue);
 }
 
 // Works on both slices and arrays
diff --git a/test/chan/powser2.go b/test/chan/powser2.go
index 6e769e98cb2..b48110819ba 100644
--- a/test/chan/powser2.go
+++ b/test/chan/powser2.go
@@ -126,7 +126,7 @@ func put(dat item, out *dch){
 func get(in *dch) *rat {
 	seqno++;
 	in.req <- seqno;
-	return <-in.dat;
+	return (<-in.dat).(*rat);
 }
 
 // Get one item from each of n demand channels
@@ -332,9 +332,9 @@ func Add(U, V PS) PS{
 		for {
 			<-Z.req;
 			uv = get2(U,V);
-			switch end(uv[0])+2*end(uv[1]) {
+			switch end(uv[0].(*rat))+2*end(uv[1].(*rat)) {
 			case 0:
-				Z.dat <- add(uv[0], uv[1]);
+				Z.dat <- add(uv[0].(*rat), uv[1].(*rat));
 			case 1:
 				Z.dat <- uv[1];
 				copy(V,Z);
@@ -448,13 +448,13 @@ func Mul(U, V PS) PS{
 	go func(U, V, Z PS){
 		<-Z.req;
 		uv := get2(U,V);
-		if end(uv[0])!=0 || end(uv[1]) != 0 {
+		if end(uv[0].(*rat))!=0 || end(uv[1].(*rat)) != 0 {
 			Z.dat <- finis;
 		} else {
-			Z.dat <- mul(uv[0],uv[1]);
+			Z.dat <- mul(uv[0].(*rat),uv[1].(*rat));
 			UU := Split(U);
 			VV := Split(V);
-			W := Add(Cmul(uv[0],VV[0]),Cmul(uv[1],UU[0]));
+			W := Add(Cmul(uv[0].(*rat),VV[0]),Cmul(uv[1].(*rat),UU[0]));
 			<-Z.req;
 			Z.dat <- get(W);
 			copy(Add(W,Mul(UU[1],VV[1])),Z);
diff --git a/test/fixedbugs/bug027.go b/test/fixedbugs/bug027.go
index 16300502b88..acc295d51aa 100644
--- a/test/fixedbugs/bug027.go
+++ b/test/fixedbugs/bug027.go
@@ -46,7 +46,7 @@ func main() {
 	v.Insert(i0);
 	for i := 0; i < v.nelem; i++ {
 		var x *I;
-		x = v.At(i);
+		x = v.At(i).(*I);
 		print(i, " ", x.val, "\n");  // prints correct list
 	}
 	for i := 0; i < v.nelem; i++ {
diff --git a/test/fixedbugs/bug054.go b/test/fixedbugs/bug054.go
index 0ed5d07082f..c8a2272c236 100644
--- a/test/fixedbugs/bug054.go
+++ b/test/fixedbugs/bug054.go
@@ -23,10 +23,7 @@ type TStruct struct {
 }
 
 func (s *TStruct) field(i int) *TStruct {
-	// works if we say
-	//	t := s.fields.At(i);
-	//	return t;
-	return s.fields.At(i);
+	return s.fields.At(i).(*TStruct);
 }
 
 func main() {
diff --git a/test/fixedbugs/bug089.go b/test/fixedbugs/bug089.go
index 296e9e6d6d4..e3d8ff66bb5 100644
--- a/test/fixedbugs/bug089.go
+++ b/test/fixedbugs/bug089.go
@@ -17,5 +17,5 @@ var	i2	I2;
 func
 main()
 {
-	i2 = e();	// bug089.go:16: fatal error: agen_inter i2i
+	i2 = e().(I2);	// bug089.go:16: fatal error: agen_inter i2i
 }
diff --git a/test/fixedbugs/bug113.go b/test/fixedbugs/bug113.go
index ea75260cf28..14bd0769263 100644
--- a/test/fixedbugs/bug113.go
+++ b/test/fixedbugs/bug113.go
@@ -11,10 +11,10 @@ func foo2(i int32) int32 { return i }
 func main() {
   var i I;
   i = 1;
-  var v1 int = i;
+  var v1 = i.(int);
   if foo1(v1) != 1 { panicln(1) }
-  var v2 int32 = int32(i.(int));
+  var v2 = int32(i.(int));
   if foo2(v2) != 1 { panicln(2) }
-  var v3 int32 = i; // This implicit type conversion should fail at runtime.
+  var v3 = i.(int32); // This type conversion should fail at runtime.
   if foo2(v3) != 1 { panicln(3) }
 }
diff --git a/test/interface2.go b/test/interface2.go
index 1db033887f3..53676787ff6 100644
--- a/test/interface2.go
+++ b/test/interface2.go
@@ -17,7 +17,7 @@ func main() {
 	var i I;
 	var e interface {};
 	e = s;
-	i = e;
+	i = e.(I);
 }
 
 // hide S down here to avoid static warning
diff --git a/test/interface5.go b/test/interface5.go
index 2e273ddddb5..86036a778be 100644
--- a/test/interface5.go
+++ b/test/interface5.go
@@ -12,10 +12,21 @@ var t *T
 type I interface { M() }
 var i I
 
+type I2 interface { M(); N(); }
+var i2 I2;
+
+var e interface { };
+
 func main() {
+	e = t;	// ok
+	t = e;	// ERROR "need explicit"
+
 	// neither of these can work,
 	// because i has an extra method
 	// that t does not, so i cannot contain a t.
-	i = t;	// ERROR "missing|incompatible"
-	t = i;	// ERROR "missing|incompatible"
+	i = t;	// ERROR "missing|incompatible|is not"
+	t = i;	// ERROR "missing|incompatible|is not"
+
+	i = i2;	// ok
+	i2 = i;	// ERROR "need explicit"
 }
diff --git a/test/ken/embed.go b/test/ken/embed.go
index f0c9f4ec2bc..8f4641e8116 100644
--- a/test/ken/embed.go
+++ b/test/ken/embed.go
@@ -214,7 +214,7 @@ main()
 
 	// run it thru an interface
 	i = s;
-	s = i;
+	s = i.(*S);
 
 	// same as t3
 	if s.test1() != s.a1 { panicln("t4", 1) }
diff --git a/test/ken/interbasic.go b/test/ken/interbasic.go
index 05eea395bbe..c6b982fe14d 100644
--- a/test/ken/interbasic.go
+++ b/test/ken/interbasic.go
@@ -85,21 +85,21 @@ main()
 	u32 = 4455;	ia[11] = u32;
 	u64 = 765432;	ia[12] = u64;
 
-	s = ia[0];	if s != "xxx" { panicln(0,s); }
+	s = ia[0].(string);	if s != "xxx" { panicln(0,s); }
 	i32 = int32(ia[1].(int));
 			if i32 != 12345 { panicln(1,i32); }
-	b = ia[2];	if b != true { panicln(2,b); }
+	b = ia[2].(bool);	if b != true { panicln(2,b); }
 
-	s = ia[3];	if s != "now is" { panicln(3,s); }
-	b = ia[4];	if b != false { panicln(4,b); }
+	s = ia[3].(string);	if s != "now is" { panicln(3,s); }
+	b = ia[4].(bool);	if b != false { panicln(4,b); }
 
-	i8 = ia[5];	if i8 != 29 { panicln(5,i8); }
-	i16 = ia[6];	if i16 != 994 { panicln(6,i16); }
-	i32 = ia[7];	if i32 != 3434 { panicln(7,i32); }
-	i64 = ia[8];	if i64 != 1234567 { panicln(8,i64); }
+	i8 = ia[5].(int8);	if i8 != 29 { panicln(5,i8); }
+	i16 = ia[6].(int16);	if i16 != 994 { panicln(6,i16); }
+	i32 = ia[7].(int32);	if i32 != 3434 { panicln(7,i32); }
+	i64 = ia[8].(int64);	if i64 != 1234567 { panicln(8,i64); }
 
-	u8 = ia[9];	if u8 != 12 { panicln(5,u8); }
-	u16 = ia[10];	if u16 != 799 { panicln(6,u16); }
-	u32 = ia[11];	if u32 != 4455 { panicln(7,u32); }
-	u64 = ia[12];	if u64 != 765432 { panicln(8,u64); }
+	u8 = ia[9].(uint8);	if u8 != 12 { panicln(5,u8); }
+	u16 = ia[10].(uint16);	if u16 != 799 { panicln(6,u16); }
+	u32 = ia[11].(uint32);	if u32 != 4455 { panicln(7,u32); }
+	u64 = ia[12].(uint64);	if u64 != 765432 { panicln(8,u64); }
 }
diff --git a/test/ken/interfun.go b/test/ken/interfun.go
index 97db8931684..876d94128dc 100644
--- a/test/ken/interfun.go
+++ b/test/ken/interfun.go
@@ -49,16 +49,16 @@ main()
 	if s.g() != 6 { panic(12); }
 
 	i1 = s;		// convert S to I1
-	i2 = i1;	// convert I1 to I2
+	i2 = i1.(I2);	// convert I1 to I2
 
 	// call interface
 	if i1.f() != 5 { panic(21); }
 	if i2.f() != 5 { panic(22); }
 	if i2.g() != 6 { panic(23); }
 
-	g = i1;		// convert I1 to S
+	g = i1.(*S);		// convert I1 to S
 	if g != s { panic(31); }
 
-	g = i2;		// convert I2 to S
+	g = i2.(*S);		// convert I2 to S
 	if g != s { panic(32); }
 }
diff --git a/usr/gri/pretty/parser.go b/usr/gri/pretty/parser.go
index 189fcf43ca1..b5cbcd72bf9 100644
--- a/usr/gri/pretty/parser.go
+++ b/usr/gri/pretty/parser.go
@@ -299,7 +299,7 @@ func (P *Parser) parseIdentList() AST.Expr {
 			x = last;
 		} else {
 			last.Y = P.newBinaryExpr(pos, Scanner.COMMA, last.Y, y);
-			last = last.Y;
+			last = last.Y.(*AST.BinaryExpr);
 		}
 	}
 
@@ -987,7 +987,7 @@ func (P *Parser) parseCompositeElements() AST.Expr {
 				x = last;
 			} else {
 				last.Y = P.newBinaryExpr(pos, Scanner.COMMA, last.Y, y);
-				last = last.Y;
+				last = last.Y.(*AST.BinaryExpr);
 			}
 
 			if P.tok == Scanner.COMMA {