diff --git a/go/types/call.go b/go/types/call.go
index 2ca943cf..8f77620f 100644
--- a/go/types/call.go
+++ b/go/types/call.go
@@ -140,7 +140,7 @@ func unpack(get getter, n int, allowCommaOk bool) (getter, int, bool) {
 		if x0.mode == mapindex || x0.mode == commaok {
 			// comma-ok value
 			if allowCommaOk {
-				a := [2]Type{x0.typ, Typ[Bool]}
+				a := [2]Type{x0.typ, Typ[UntypedBool]}
 				return func(x *operand, i int) {
 					x.mode = value
 					x.expr = x0.expr
diff --git a/go/types/testdata/expr3.src b/go/types/testdata/expr3.src
index abed361b..3e710517 100644
--- a/go/types/testdata/expr3.src
+++ b/go/types/testdata/expr3.src
@@ -98,7 +98,7 @@ func indexes() {
 	// ok is of type bool
 	type mybool bool
 	var ok mybool
-	_, ok = m /* ERROR "cannot assign" */ ["bar"]
+	_, ok = m["bar"]
 	_ = ok
 
 
@@ -372,7 +372,7 @@ func type_asserts() {
 
 	// ok value is of type bool
 	var myok mybool
-	_, myok = e /* ERROR "cannot assign" */ .(int)
+	_, myok = e.(int)
 	_ = myok
 
 	var t I
diff --git a/go/types/testdata/stmt0.src b/go/types/testdata/stmt0.src
index 9a98a1e1..026d784e 100644
--- a/go/types/testdata/stmt0.src
+++ b/go/types/testdata/stmt0.src
@@ -95,14 +95,18 @@ func assignments1() {
 }
 
 func assignments2() {
+	type mybool bool
 	var m map[string][]bool
 	var s []bool
 	var b bool
+	var d mybool
 	_ = s
 	_ = b
+	_ = d
 
 	// assignments to map index expressions are ok
 	s, b = m["foo"]
+	_, d = m["bar"]
 	m["foo"] = nil
 	m["foo"] = nil /* ERROR assignment count mismatch */ , false
 	_ = append(m["foo"])
@@ -110,6 +114,7 @@ func assignments2() {
 
 	var c chan int
 	_, b = <-c
+	_, d = <-c
 	<- /* ERROR cannot assign */ c = 0
 	<-c = 0 /* ERROR assignment count mismatch */ , false