diff --git a/src/cmd/gc/const.c b/src/cmd/gc/const.c
index 4575ff6da45..895f264313b 100644
--- a/src/cmd/gc/const.c
+++ b/src/cmd/gc/const.c
@@ -186,6 +186,10 @@ convlit1(Node **np, Type *t, int explicit)
 	return;
 
 bad:
+	if(!n->diag) {
+		yyerror("cannot convert %#N to type %T", n, t);
+		n->diag = 1;
+	}
 	if(isideal(n->type)) {
 		defaultlit(&n, T);
 		*np = n;
diff --git a/src/cmd/gc/walk.c b/src/cmd/gc/walk.c
index 587119c96fa..211efaec94a 100644
--- a/src/cmd/gc/walk.c
+++ b/src/cmd/gc/walk.c
@@ -180,8 +180,11 @@ walkdef(Node *n)
 			goto ret;
 		}
 		t = n->type;
-		if(t != T)
+		if(t != T) {
 			convlit(&e, t);
+			if(!isint[t->etype] && !isfloat[t->etype] && t->etype != TSTRING)
+				yyerror("invalid constant type %T", t);
+		}
 		n->val = e->val;
 		n->type = e->type;
 		break;
diff --git a/test/bugs/bug238.go b/test/bugs/bug238.go
deleted file mode 100644
index a5737d66028..00000000000
--- a/test/bugs/bug238.go
+++ /dev/null
@@ -1,19 +0,0 @@
-// errchk $G -e $D/$F.go
-
-// Copyright 2009 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.
-
-// Test case for issue 471. This file shouldn't compile.
-
-package main
-
-const a *int = 1        // ERROR "wrong|incompatible"
-const b [2]int = 2      // ERROR "wrong|incompatible"
-const c map[int]int = 3 // ERROR "wrong|incompatible"
-const d chan int = 4    // ERROR "wrong|incompatible"
-const e func() = 5      // ERROR "wrong|incompatible"
-const f struct{} = 6    // ERROR "wrong|incompatible"
-const g interface{} = 7 // ERROR "wrong|incompatible"
-
-func main() { println(a, b, c, d, e, f, g) }
diff --git a/test/fixedbugs/bug238.go b/test/fixedbugs/bug238.go
new file mode 100644
index 00000000000..3ceacf51d7f
--- /dev/null
+++ b/test/fixedbugs/bug238.go
@@ -0,0 +1,19 @@
+// errchk $G -e $D/$F.go
+
+// Copyright 2009 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.
+
+// Test case for issue 471. This file shouldn't compile.
+
+package main
+
+const a *int = 1        // ERROR "convert|wrong|incompatible"
+const b [2]int = 2      // ERROR "convert|wrong|incompatible"
+const c map[int]int = 3 // ERROR "convert|wrong|incompatible"
+const d chan int = 4    // ERROR "convert|wrong|incompatible"
+const e func() = 5      // ERROR "convert|wrong|incompatible"
+const f struct{} = 6    // ERROR "convert|wrong|incompatible"
+const g interface{} = 7 // ERROR "constant|wrong|incompatible"
+
+func main() { println(a, b, c, d, e, f, g) }
diff --git a/test/golden.out b/test/golden.out
index 0795adf44ee..ae04f70bb3b 100644
--- a/test/golden.out
+++ b/test/golden.out
@@ -144,18 +144,3 @@ throw: interface conversion
 panic PC=xxx
 
 == bugs/
-
-=========== bugs/bug219.go
-bugs/bug219.go:16: syntax error near if
-BUG: bug219
-
-=========== bugs/bug238.go
-BUG: errchk: command succeeded unexpectedly
-
-=========== bugs/bug239.go
-bugs/bug239.go:11: imported and not used: unsafe
-bugs/bug239.go:15: undefined: Sizeof
-BUG: bug239
-
-=========== bugs/bug240.go
-BUG: errchk: command succeeded unexpectedly