diff --git a/src/cmd/compile/internal/gc/const.go b/src/cmd/compile/internal/gc/const.go
index 399d0148bb..c0ed8192d9 100644
--- a/src/cmd/compile/internal/gc/const.go
+++ b/src/cmd/compile/internal/gc/const.go
@@ -1072,12 +1072,7 @@ func defaultlit2(l *Node, r *Node, force bool) (*Node, *Node) {
 		return l, r
 	}
 
-	nn := l
-	if ctype(r.Type) > ctype(l.Type) {
-		nn = r
-	}
-
-	t := defaultType(nn.Type)
+	t := defaultType(mixUntyped(l.Type, r.Type))
 	l = convlit(l, t)
 	r = convlit(r, t)
 	return l, r
@@ -1102,6 +1097,14 @@ func ctype(t *types.Type) Ctype {
 	panic("unreachable")
 }
 
+func mixUntyped(t1, t2 *types.Type) *types.Type {
+	t := t1
+	if ctype(t2) > ctype(t1) {
+		t = t2
+	}
+	return t
+}
+
 func defaultType(t *types.Type) *types.Type {
 	if !t.IsUntyped() || t.Etype == TNIL {
 		return t
diff --git a/src/cmd/compile/internal/gc/typecheck.go b/src/cmd/compile/internal/gc/typecheck.go
index 2654177c25..12c99bf48f 100644
--- a/src/cmd/compile/internal/gc/typecheck.go
+++ b/src/cmd/compile/internal/gc/typecheck.go
@@ -717,18 +717,7 @@ func typecheck1(n *Node, top int) (res *Node) {
 		}
 
 		if t.Etype == TIDEAL {
-			switch {
-			case l.Type == types.Idealcomplex || r.Type == types.Idealcomplex:
-				t = types.Idealcomplex
-			case l.Type == types.Idealfloat || r.Type == types.Idealfloat:
-				t = types.Idealfloat
-			case l.Type == types.Idealrune || r.Type == types.Idealrune:
-				t = types.Idealrune
-			case l.Type == types.Idealint || r.Type == types.Idealint:
-				t = types.Idealint
-			default:
-				Fatalf("bad untyped type: %v", t)
-			}
+			t = mixUntyped(l.Type, r.Type)
 		}
 		if dt := defaultType(t); !okfor[op][dt.Etype] {
 			yyerror("invalid operation: %v (operator %v not defined on %v)", n, op, t)