diff --git a/src/cmd/compile/internal/noder/noder.go b/src/cmd/compile/internal/noder/noder.go
index 8c456e4561..4c7c9fc322 100644
--- a/src/cmd/compile/internal/noder/noder.go
+++ b/src/cmd/compile/internal/noder/noder.go
@@ -689,7 +689,7 @@ func (p *noder) expr(expr syntax.Expr) ir.Node {
 		if expr.Kind == syntax.RuneLit {
 			n.SetType(types.UntypedRune)
 		}
-		n.SetDiag(expr.Bad) // avoid follow-on errors if there was a syntax error
+		n.SetDiag(expr.Bad || n.Val().Kind() == constant.Unknown) // avoid follow-on errors if there was a syntax error
 		return n
 	case *syntax.CompositeLit:
 		n := ir.NewCompLitExpr(p.pos(expr), ir.OCOMPLIT, p.typeExpr(expr.Type), nil)
diff --git a/src/cmd/compile/internal/typecheck/typecheck.go b/src/cmd/compile/internal/typecheck/typecheck.go
index 647465af4f..548c1af85c 100644
--- a/src/cmd/compile/internal/typecheck/typecheck.go
+++ b/src/cmd/compile/internal/typecheck/typecheck.go
@@ -482,7 +482,9 @@ func typecheck1(n ir.Node, top int) ir.Node {
 
 	case ir.OLITERAL:
 		if n.Sym() == nil && n.Type() == nil {
-			base.Fatalf("literal missing type: %v", n)
+			if !n.Diag() {
+				base.Fatalf("literal missing type: %v", n)
+			}
 		}
 		return n
 
diff --git a/test/char_lit1.go b/test/char_lit1.go
index 489744b6e9..8899aff83a 100644
--- a/test/char_lit1.go
+++ b/test/char_lit1.go
@@ -1,4 +1,4 @@
-// errorcheck
+// errorcheck -d=panic
 
 // Copyright 2009 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
diff --git a/test/fixedbugs/issue20232.go b/test/fixedbugs/issue20232.go
index 7a0300a4c4..846843dccb 100644
--- a/test/fixedbugs/issue20232.go
+++ b/test/fixedbugs/issue20232.go
@@ -1,4 +1,4 @@
-// errorcheck
+// errorcheck -d=panic
 
 // Copyright 2017 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style