diff --git a/test/bugs/bug239.go b/test/bugs/bug239.go
new file mode 100644
index 00000000000..32c3d7e1c1d
--- /dev/null
+++ b/test/bugs/bug239.go
@@ -0,0 +1,21 @@
+// $G $D/$F.go || echo BUG: bug239
+
+// 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 475. This file should compile.
+
+package main
+
+import . "unsafe"
+
+func main() {
+	var x int
+	println(Sizeof(x))
+}
+
+/*
+bug239.go:11: imported and not used: unsafe
+bug239.go:15: undefined: Sizeof
+*/
diff --git a/test/bugs/bug240.go b/test/bugs/bug240.go
new file mode 100644
index 00000000000..dc7cdd8963a
--- /dev/null
+++ b/test/bugs/bug240.go
@@ -0,0 +1,20 @@
+// 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.
+
+package main
+
+import . "unsafe"
+
+func main() {
+	var x int
+	println(unsafe.Sizeof(x)) // ERROR "undefined"
+}
+
+/*
+After a '.' import, "unsafe" shouldn't be defined as
+an identifier. 6g complains correctly for imports other
+than "unsafe".
+*/
diff --git a/test/golden.out b/test/golden.out
index 8b092f95ca4..0795adf44ee 100644
--- a/test/golden.out
+++ b/test/golden.out
@@ -151,3 +151,11 @@ 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