diff --git a/src/cmd/gc/dcl.c b/src/cmd/gc/dcl.c
index bf226d92a3..7bc9ce988e 100644
--- a/src/cmd/gc/dcl.c
+++ b/src/cmd/gc/dcl.c
@@ -188,6 +188,9 @@ declare(Node *n, int ctxt)
 	if(importpkg == nil && !typecheckok && s->pkg != localpkg)
 		yyerror("cannot declare name %S", s);
 
+	if(ctxt == PEXTERN && strcmp(s->name, "init") == 0)
+		yyerror("cannot declare init - must be func", s);
+
 	gen = 0;
 	if(ctxt == PEXTERN) {
 		externdcl = list(externdcl, n);
diff --git a/test/fixedbugs/issue3705.go b/test/fixedbugs/issue3705.go
new file mode 100644
index 0000000000..c19bcea1cc
--- /dev/null
+++ b/test/fixedbugs/issue3705.go
@@ -0,0 +1,9 @@
+// errorcheck
+
+// Copyright 2012 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 init() // ERROR "missing function body"
diff --git a/test/fixedbugs/issue4517a.go b/test/fixedbugs/issue4517a.go
new file mode 100644
index 0000000000..a1b6b57e97
--- /dev/null
+++ b/test/fixedbugs/issue4517a.go
@@ -0,0 +1,9 @@
+// errorcheck
+
+// Copyright 2012 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
+
+var init = 1 // ERROR "cannot declare init - must be func"
diff --git a/test/fixedbugs/issue4517b.go b/test/fixedbugs/issue4517b.go
new file mode 100644
index 0000000000..f04103ff5b
--- /dev/null
+++ b/test/fixedbugs/issue4517b.go
@@ -0,0 +1,9 @@
+// errorcheck
+
+// Copyright 2012 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
+
+const init = 1 // ERROR "cannot declare init - must be func"
diff --git a/test/fixedbugs/issue4517c.go b/test/fixedbugs/issue4517c.go
new file mode 100644
index 0000000000..47b21cf408
--- /dev/null
+++ b/test/fixedbugs/issue4517c.go
@@ -0,0 +1,9 @@
+// errorcheck
+
+// Copyright 2012 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
+
+type init byte // ERROR "cannot declare init - must be func"