diff --git a/src/cmd/compile/internal/types/size.go b/src/cmd/compile/internal/types/size.go
index 4c7378560cc..ef23cdf5fe3 100644
--- a/src/cmd/compile/internal/types/size.go
+++ b/src/cmd/compile/internal/types/size.go
@@ -100,7 +100,7 @@ func expandiface(t *Type) {
 	}
 
 	for _, m := range t.Methods().Slice() {
-		if m.Sym != nil {
+		if m.Sym != nil || m.Type == nil {
 			continue
 		}
 
diff --git a/test/fixedbugs/issue20245.go b/test/fixedbugs/issue20245.go
index b07dbe20de6..20258231d12 100644
--- a/test/fixedbugs/issue20245.go
+++ b/test/fixedbugs/issue20245.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
diff --git a/test/fixedbugs/issue22921.go b/test/fixedbugs/issue22921.go
index 5336ba34109..cdd77fb24f2 100644
--- a/test/fixedbugs/issue22921.go
+++ b/test/fixedbugs/issue22921.go
@@ -1,4 +1,4 @@
-// errorcheck
+// errorcheck -d=panic
 
 // Copyright 2020 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
diff --git a/test/fixedbugs/issue27938.go b/test/fixedbugs/issue27938.go
index ed974e642df..2589e1eff8d 100644
--- a/test/fixedbugs/issue27938.go
+++ b/test/fixedbugs/issue27938.go
@@ -1,4 +1,4 @@
-// errorcheck
+// errorcheck -d=panic
 
 // Copyright 2018 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style