src/go/types/call.go | 1 -

diff --git a/src/go/types/call.go b/src/go/types/call.go
index 631ea426c6bbf42e5fe613e4936942a2e253d055..336b526a2843d3b977986a07ba3b9bfeef6a4e8d 100644
--- a/src/go/types/call.go
+++ b/src/go/types/call.go
@@ -224,7 +224,6 @@
 		// exactly one (possibly invalid or comma-ok) value
 		xlist = []*operand{&x}
 		if allowCommaOk && (x.mode == mapindex || x.mode == commaok || x.mode == commaerr) {
-			x.mode = value
 			x2 := &operand{mode: value, expr: e, typ: Typ[UntypedBool]}
 			if x.mode == commaerr {
 				x2.typ = universeError