diff --git a/src/cmd/compile/internal/types2/assignments.go b/src/cmd/compile/internal/types2/assignments.go
index 35fb3f5b14..dd814c2e83 100644
--- a/src/cmd/compile/internal/types2/assignments.go
+++ b/src/cmd/compile/internal/types2/assignments.go
@@ -266,7 +266,7 @@ func (check *Checker) typesSummary(list []Type, variadic bool) string {
 		case t == nil:
 			fallthrough // should not happen but be cautious
 		case t == Typ[Invalid]:
-			s = "<T>"
+			s = "unknown type"
 		case isUntyped(t):
 			if isNumeric(t) {
 				// Do not imply a specific type requirement:
diff --git a/src/go/types/assignments.go b/src/go/types/assignments.go
index a7a247b99f..a3b28d0e22 100644
--- a/src/go/types/assignments.go
+++ b/src/go/types/assignments.go
@@ -260,7 +260,7 @@ func (check *Checker) typesSummary(list []Type, variadic bool) string {
 		case t == nil:
 			fallthrough // should not happen but be cautious
 		case t == Typ[Invalid]:
-			s = "<T>"
+			s = "unknown type"
 		case isUntyped(t):
 			if isNumeric(t) {
 				// Do not imply a specific type requirement:
diff --git a/src/internal/types/testdata/fixedbugs/issue58742.go b/src/internal/types/testdata/fixedbugs/issue58742.go
new file mode 100644
index 0000000000..b649a49774
--- /dev/null
+++ b/src/internal/types/testdata/fixedbugs/issue58742.go
@@ -0,0 +1,18 @@
+// Copyright 2023 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package p
+
+func _() (int, UndefinedType /* ERROR "undefined: UndefinedType" */ , string)  {
+	return 0 // ERROR "not enough return values\n\thave (number)\n\twant (int, unknown type, string)"
+}
+
+func _() (int, UndefinedType /* ERROR "undefined: UndefinedType" */ ) {
+	return 0, 1, 2 // ERROR "too many return values\n\thave (number, number, number)\n\twant (int, unknown type)"
+}
+
+// test case from issue
+func _() UndefinedType /* ERROR "undefined: UndefinedType" */ {
+	return // ERROR "not enough return values\n\thave ()\n\twant (unknown type)"
+}