diff --git a/src/go/internal/gccgoimporter/importer_test.go b/src/go/internal/gccgoimporter/importer_test.go
index 4fa01c762c..f3bcadbaf7 100644
--- a/src/go/internal/gccgoimporter/importer_test.go
+++ b/src/go/internal/gccgoimporter/importer_test.go
@@ -34,7 +34,7 @@ func runImporterTest(t *testing.T, imp Importer, initmap map[*types.Package]Init
 			return
 		}
 
-		got := types.ObjectString(pkg, obj)
+		got := types.ObjectString(obj, types.RelativeTo(pkg))
 		if got != test.want {
 			t.Errorf("%s: got %q; want %q", test.name, got, test.want)
 		}
diff --git a/src/go/internal/gcimporter/gcimporter_test.go b/src/go/internal/gcimporter/gcimporter_test.go
index fe4a758cd4..85846a1348 100644
--- a/src/go/internal/gcimporter/gcimporter_test.go
+++ b/src/go/internal/gcimporter/gcimporter_test.go
@@ -165,7 +165,7 @@ func TestImportedTypes(t *testing.T) {
 			continue
 		}
 
-		got := types.ObjectString(pkg, obj)
+		got := types.ObjectString(obj, types.RelativeTo(pkg))
 		if got != test.want {
 			t.Errorf("%s: got %q; want %q", test.name, got, test.want)
 		}
diff --git a/src/go/types/errors.go b/src/go/types/errors.go
index 0a9dd0e19b..0c0049b1f3 100644
--- a/src/go/types/errors.go
+++ b/src/go/types/errors.go
@@ -23,6 +23,13 @@ func unreachable() {
 	panic("unreachable")
 }
 
+func (check *Checker) qualifier(pkg *Package) string {
+	if pkg != check.pkg {
+		return pkg.path
+	}
+	return ""
+}
+
 func (check *Checker) sprintf(format string, args ...interface{}) string {
 	for i, arg := range args {
 		switch a := arg.(type) {
@@ -31,15 +38,15 @@ func (check *Checker) sprintf(format string, args ...interface{}) string {
 		case operand:
 			panic("internal error: should always pass *operand")
 		case *operand:
-			arg = operandString(check.pkg, a)
+			arg = operandString(a, check.qualifier)
 		case token.Pos:
 			arg = check.fset.Position(a).String()
 		case ast.Expr:
 			arg = ExprString(a)
 		case Object:
-			arg = ObjectString(check.pkg, a)
+			arg = ObjectString(a, check.qualifier)
 		case Type:
-			arg = TypeString(check.pkg, a)
+			arg = TypeString(a, check.qualifier)
 		}
 		args[i] = arg
 	}
diff --git a/src/go/types/example_test.go b/src/go/types/example_test.go
index 997aed33d1..8882e5063a 100644
--- a/src/go/types/example_test.go
+++ b/src/go/types/example_test.go
@@ -199,7 +199,7 @@ func fib(x int) int {
 	for obj, uses := range usesByObj {
 		sort.Strings(uses)
 		item := fmt.Sprintf("%s:\n  defined at %s\n  used at %s",
-			types.ObjectString(pkg, obj),
+			types.ObjectString(obj, types.RelativeTo(pkg)),
 			fset.Position(obj.Pos()),
 			strings.Join(uses, ", "))
 		items = append(items, item)
diff --git a/src/go/types/object.go b/src/go/types/object.go
index ebbd760df4..62b39c6b81 100644
--- a/src/go/types/object.go
+++ b/src/go/types/object.go
@@ -207,7 +207,7 @@ func NewFunc(pos token.Pos, pkg *Package, name string, sig *Signature) *Func {
 // function or method obj.
 func (obj *Func) FullName() string {
 	var buf bytes.Buffer
-	writeFuncName(&buf, nil, obj)
+	writeFuncName(&buf, obj, nil)
 	return buf.String()
 }
 
@@ -241,7 +241,7 @@ type Nil struct {
 	object
 }
 
-func writeObject(buf *bytes.Buffer, this *Package, obj Object) {
+func writeObject(buf *bytes.Buffer, obj Object, qf Qualifier) {
 	typ := obj.Type()
 	switch obj := obj.(type) {
 	case *PkgName:
@@ -267,9 +267,9 @@ func writeObject(buf *bytes.Buffer, this *Package, obj Object) {
 
 	case *Func:
 		buf.WriteString("func ")
-		writeFuncName(buf, this, obj)
+		writeFuncName(buf, obj, qf)
 		if typ != nil {
-			WriteSignature(buf, this, typ.(*Signature))
+			WriteSignature(buf, typ.(*Signature), qf)
 		}
 		return
 
@@ -291,39 +291,52 @@ func writeObject(buf *bytes.Buffer, this *Package, obj Object) {
 
 	buf.WriteByte(' ')
 
-	// For package-level objects, package-qualify the name,
-	// except for intra-package references (this != nil).
-	if pkg := obj.Pkg(); pkg != nil && this != pkg && pkg.scope.Lookup(obj.Name()) == obj {
-		buf.WriteString(pkg.path)
-		buf.WriteByte('.')
+	// For package-level objects, qualify the name.
+	if obj.Pkg() != nil && obj.Pkg().scope.Lookup(obj.Name()) == obj {
+		writePackage(buf, obj.Pkg(), qf)
 	}
 	buf.WriteString(obj.Name())
 	if typ != nil {
 		buf.WriteByte(' ')
-		WriteType(buf, this, typ)
+		WriteType(buf, typ, qf)
+	}
+}
+
+func writePackage(buf *bytes.Buffer, pkg *Package, qf Qualifier) {
+	if pkg == nil {
+		return
+	}
+	var s string
+	if qf != nil {
+		s = qf(pkg)
+	} else {
+		s = pkg.Path()
+	}
+	if s != "" {
+		buf.WriteString(s)
+		buf.WriteByte('.')
 	}
 }
 
 // ObjectString returns the string form of obj.
-// Object and type names are printed package-qualified
-// only if they do not belong to this package.
-//
-func ObjectString(this *Package, obj Object) string {
+// The Qualifier controls the printing of
+// package-level objects, and may be nil.
+func ObjectString(obj Object, qf Qualifier) string {
 	var buf bytes.Buffer
-	writeObject(&buf, this, obj)
+	writeObject(&buf, obj, qf)
 	return buf.String()
 }
 
-func (obj *PkgName) String() string  { return ObjectString(nil, obj) }
-func (obj *Const) String() string    { return ObjectString(nil, obj) }
-func (obj *TypeName) String() string { return ObjectString(nil, obj) }
-func (obj *Var) String() string      { return ObjectString(nil, obj) }
-func (obj *Func) String() string     { return ObjectString(nil, obj) }
-func (obj *Label) String() string    { return ObjectString(nil, obj) }
-func (obj *Builtin) String() string  { return ObjectString(nil, obj) }
-func (obj *Nil) String() string      { return ObjectString(nil, obj) }
+func (obj *PkgName) String() string  { return ObjectString(obj, nil) }
+func (obj *Const) String() string    { return ObjectString(obj, nil) }
+func (obj *TypeName) String() string { return ObjectString(obj, nil) }
+func (obj *Var) String() string      { return ObjectString(obj, nil) }
+func (obj *Func) String() string     { return ObjectString(obj, nil) }
+func (obj *Label) String() string    { return ObjectString(obj, nil) }
+func (obj *Builtin) String() string  { return ObjectString(obj, nil) }
+func (obj *Nil) String() string      { return ObjectString(obj, nil) }
 
-func writeFuncName(buf *bytes.Buffer, this *Package, f *Func) {
+func writeFuncName(buf *bytes.Buffer, f *Func, qf Qualifier) {
 	if f.typ != nil {
 		sig := f.typ.(*Signature)
 		if recv := sig.Recv(); recv != nil {
@@ -335,13 +348,12 @@ func writeFuncName(buf *bytes.Buffer, this *Package, f *Func) {
 				// Don't print it in full.
 				buf.WriteString("interface")
 			} else {
-				WriteType(buf, this, recv.Type())
+				WriteType(buf, recv.Type(), qf)
 			}
 			buf.WriteByte(')')
 			buf.WriteByte('.')
-		} else if f.pkg != nil && f.pkg != this {
-			buf.WriteString(f.pkg.path)
-			buf.WriteByte('.')
+		} else if f.pkg != nil {
+			writePackage(buf, f.pkg, qf)
 		}
 	}
 	buf.WriteString(f.name)
diff --git a/src/go/types/operand.go b/src/go/types/operand.go
index 8d167067d5..a7d3b0aaee 100644
--- a/src/go/types/operand.go
+++ b/src/go/types/operand.go
@@ -93,7 +93,7 @@ func (x *operand) pos() token.Pos {
 // commaok    <expr> (<untyped kind> <mode>                    )
 // commaok    <expr> (               <mode>       of type <typ>)
 //
-func operandString(this *Package, x *operand) string {
+func operandString(x *operand, qf Qualifier) string {
 	var buf bytes.Buffer
 
 	var expr string
@@ -104,7 +104,7 @@ func operandString(this *Package, x *operand) string {
 		case builtin:
 			expr = predeclaredFuncs[x.id].name
 		case typexpr:
-			expr = TypeString(this, x.typ)
+			expr = TypeString(x.typ, qf)
 		case constant:
 			expr = x.val.String()
 		}
@@ -146,7 +146,7 @@ func operandString(this *Package, x *operand) string {
 	if hasType {
 		if x.typ != Typ[Invalid] {
 			buf.WriteString(" of type ")
-			WriteType(&buf, this, x.typ)
+			WriteType(&buf, x.typ, qf)
 		} else {
 			buf.WriteString(" with invalid type")
 		}
@@ -161,7 +161,7 @@ func operandString(this *Package, x *operand) string {
 }
 
 func (x *operand) String() string {
-	return operandString(nil, x)
+	return operandString(x, nil)
 }
 
 // setConst sets x to the untyped constant for literal lit.
diff --git a/src/go/types/selection.go b/src/go/types/selection.go
index 1c7016550a..124e0d39f0 100644
--- a/src/go/types/selection.go
+++ b/src/go/types/selection.go
@@ -105,18 +105,18 @@ func (s *Selection) Index() []int { return s.index }
 // x to f in x.f.
 func (s *Selection) Indirect() bool { return s.indirect }
 
-func (s *Selection) String() string { return SelectionString(nil, s) }
+func (s *Selection) String() string { return SelectionString(s, nil) }
 
 // SelectionString returns the string form of s.
-// Type names are printed package-qualified
-// only if they do not belong to this package.
+// The Qualifier controls the printing of
+// package-level objects, and may be nil.
 //
 // Examples:
 //	"field (T) f int"
 //	"method (T) f(X) Y"
 //	"method expr (T) f(X) Y"
 //
-func SelectionString(this *Package, s *Selection) string {
+func SelectionString(s *Selection, qf Qualifier) string {
 	var k string
 	switch s.kind {
 	case FieldVal:
@@ -131,13 +131,13 @@ func SelectionString(this *Package, s *Selection) string {
 	var buf bytes.Buffer
 	buf.WriteString(k)
 	buf.WriteByte('(')
-	WriteType(&buf, this, s.Recv())
+	WriteType(&buf, s.Recv(), qf)
 	fmt.Fprintf(&buf, ") %s", s.obj.Name())
 	if T := s.Type(); s.kind == FieldVal {
 		buf.WriteByte(' ')
-		WriteType(&buf, this, T)
+		WriteType(&buf, T, qf)
 	} else {
-		WriteSignature(&buf, this, T.(*Signature))
+		WriteSignature(&buf, T.(*Signature), qf)
 	}
 	return buf.String()
 }
diff --git a/src/go/types/type.go b/src/go/types/type.go
index 3d1af20a10..1df8b45b28 100644
--- a/src/go/types/type.go
+++ b/src/go/types/type.go
@@ -441,14 +441,14 @@ func (t *Map) Underlying() Type       { return t }
 func (t *Chan) Underlying() Type      { return t }
 func (t *Named) Underlying() Type     { return t.underlying }
 
-func (t *Basic) String() string     { return TypeString(nil, t) }
-func (t *Array) String() string     { return TypeString(nil, t) }
-func (t *Slice) String() string     { return TypeString(nil, t) }
-func (t *Struct) String() string    { return TypeString(nil, t) }
-func (t *Pointer) String() string   { return TypeString(nil, t) }
-func (t *Tuple) String() string     { return TypeString(nil, t) }
-func (t *Signature) String() string { return TypeString(nil, t) }
-func (t *Interface) String() string { return TypeString(nil, t) }
-func (t *Map) String() string       { return TypeString(nil, t) }
-func (t *Chan) String() string      { return TypeString(nil, t) }
-func (t *Named) String() string     { return TypeString(nil, t) }
+func (t *Basic) String() string     { return TypeString(t, nil) }
+func (t *Array) String() string     { return TypeString(t, nil) }
+func (t *Slice) String() string     { return TypeString(t, nil) }
+func (t *Struct) String() string    { return TypeString(t, nil) }
+func (t *Pointer) String() string   { return TypeString(t, nil) }
+func (t *Tuple) String() string     { return TypeString(t, nil) }
+func (t *Signature) String() string { return TypeString(t, nil) }
+func (t *Interface) String() string { return TypeString(t, nil) }
+func (t *Map) String() string       { return TypeString(t, nil) }
+func (t *Chan) String() string      { return TypeString(t, nil) }
+func (t *Named) String() string     { return TypeString(t, nil) }
diff --git a/src/go/types/typestring.go b/src/go/types/typestring.go
index 6f527bbed0..bd62f4dc22 100644
--- a/src/go/types/typestring.go
+++ b/src/go/types/typestring.go
@@ -11,6 +11,33 @@ import (
 	"fmt"
 )
 
+// A Qualifier controls how named package-level objects are printed in
+// calls to TypeString, ObjectString, and SelectionString.
+//
+// These three formatting routines call the Qualifier for each
+// package-level object O, and if the Qualifier returns a non-empty
+// string p, the object is printed in the form p.O.
+// If it returns an empty string, only the object name O is printed.
+//
+// Using a nil Qualifier is equivalent to using (*Package).Path: the
+// object is qualified by the import path, e.g., "encoding/json.Marshal".
+//
+type Qualifier func(*Package) string
+
+// RelativeTo(pkg) returns a Qualifier that fully qualifies members of
+// all packages other than pkg.
+func RelativeTo(pkg *Package) Qualifier {
+	if pkg == nil {
+		return nil
+	}
+	return func(other *Package) string {
+		if pkg == other {
+			return "" // same package; unqualified
+		}
+		return other.Path()
+	}
+}
+
 // If gcCompatibilityMode is set, printing of types is modified
 // to match the representation of some types in the gc compiler:
 //
@@ -32,22 +59,22 @@ import (
 var gcCompatibilityMode bool
 
 // TypeString returns the string representation of typ.
-// Named types are printed package-qualified if they
-// do not belong to this package.
-func TypeString(this *Package, typ Type) string {
+// The Qualifier controls the printing of
+// package-level objects, and may be nil.
+func TypeString(typ Type, qf Qualifier) string {
 	var buf bytes.Buffer
-	WriteType(&buf, this, typ)
+	WriteType(&buf, typ, qf)
 	return buf.String()
 }
 
 // WriteType writes the string representation of typ to buf.
-// Named types are printed package-qualified if they
-// do not belong to this package.
-func WriteType(buf *bytes.Buffer, this *Package, typ Type) {
-	writeType(buf, this, typ, make([]Type, 8))
+// The Qualifier controls the printing of
+// package-level objects, and may be nil.
+func WriteType(buf *bytes.Buffer, typ Type, qf Qualifier) {
+	writeType(buf, typ, qf, make([]Type, 8))
 }
 
-func writeType(buf *bytes.Buffer, this *Package, typ Type, visited []Type) {
+func writeType(buf *bytes.Buffer, typ Type, qf Qualifier, visited []Type) {
 	// Theoretically, this is a quadratic lookup algorithm, but in
 	// practice deeply nested composite types with unnamed component
 	// types are uncommon. This code is likely more efficient than
@@ -81,11 +108,11 @@ func writeType(buf *bytes.Buffer, this *Package, typ Type, visited []Type) {
 
 	case *Array:
 		fmt.Fprintf(buf, "[%d]", t.len)
-		writeType(buf, this, t.elem, visited)
+		writeType(buf, t.elem, qf, visited)
 
 	case *Slice:
 		buf.WriteString("[]")
-		writeType(buf, this, t.elem, visited)
+		writeType(buf, t.elem, qf, visited)
 
 	case *Struct:
 		buf.WriteString("struct{")
@@ -97,7 +124,7 @@ func writeType(buf *bytes.Buffer, this *Package, typ Type, visited []Type) {
 				buf.WriteString(f.name)
 				buf.WriteByte(' ')
 			}
-			writeType(buf, this, f.typ, visited)
+			writeType(buf, f.typ, qf, visited)
 			if tag := t.Tag(i); tag != "" {
 				fmt.Fprintf(buf, " %q", tag)
 			}
@@ -106,14 +133,14 @@ func writeType(buf *bytes.Buffer, this *Package, typ Type, visited []Type) {
 
 	case *Pointer:
 		buf.WriteByte('*')
-		writeType(buf, this, t.base, visited)
+		writeType(buf, t.base, qf, visited)
 
 	case *Tuple:
-		writeTuple(buf, this, t, false, visited)
+		writeTuple(buf, t, false, qf, visited)
 
 	case *Signature:
 		buf.WriteString("func")
-		writeSignature(buf, this, t, visited)
+		writeSignature(buf, t, qf, visited)
 
 	case *Interface:
 		// We write the source-level methods and embedded types rather
@@ -136,7 +163,7 @@ func writeType(buf *bytes.Buffer, this *Package, typ Type, visited []Type) {
 					buf.WriteString("; ")
 				}
 				buf.WriteString(m.name)
-				writeSignature(buf, this, m.typ.(*Signature), visited)
+				writeSignature(buf, m.typ.(*Signature), qf, visited)
 			}
 		} else {
 			// print explicit interface methods and embedded types
@@ -145,22 +172,22 @@ func writeType(buf *bytes.Buffer, this *Package, typ Type, visited []Type) {
 					buf.WriteString("; ")
 				}
 				buf.WriteString(m.name)
-				writeSignature(buf, this, m.typ.(*Signature), visited)
+				writeSignature(buf, m.typ.(*Signature), qf, visited)
 			}
 			for i, typ := range t.embeddeds {
 				if i > 0 || len(t.methods) > 0 {
 					buf.WriteString("; ")
 				}
-				writeType(buf, this, typ, visited)
+				writeType(buf, typ, qf, visited)
 			}
 		}
 		buf.WriteByte('}')
 
 	case *Map:
 		buf.WriteString("map[")
-		writeType(buf, this, t.key, visited)
+		writeType(buf, t.key, qf, visited)
 		buf.WriteByte(']')
-		writeType(buf, this, t.elem, visited)
+		writeType(buf, t.elem, qf, visited)
 
 	case *Chan:
 		var s string
@@ -183,7 +210,7 @@ func writeType(buf *bytes.Buffer, this *Package, typ Type, visited []Type) {
 		if parens {
 			buf.WriteByte('(')
 		}
-		writeType(buf, this, t.elem, visited)
+		writeType(buf, t.elem, qf, visited)
 		if parens {
 			buf.WriteByte(')')
 		}
@@ -191,9 +218,8 @@ func writeType(buf *bytes.Buffer, this *Package, typ Type, visited []Type) {
 	case *Named:
 		s := "<Named w/o object>"
 		if obj := t.obj; obj != nil {
-			if pkg := obj.pkg; pkg != nil && pkg != this {
-				buf.WriteString(pkg.path)
-				buf.WriteByte('.')
+			if obj.pkg != nil {
+				writePackage(buf, obj.pkg, qf)
 			}
 			// TODO(gri): function-local named types should be displayed
 			// differently from named types at package level to avoid
@@ -208,7 +234,7 @@ func writeType(buf *bytes.Buffer, this *Package, typ Type, visited []Type) {
 	}
 }
 
-func writeTuple(buf *bytes.Buffer, this *Package, tup *Tuple, variadic bool, visited []Type) {
+func writeTuple(buf *bytes.Buffer, tup *Tuple, variadic bool, qf Qualifier, visited []Type) {
 	buf.WriteByte('(')
 	if tup != nil {
 		for i, v := range tup.vars {
@@ -230,12 +256,12 @@ func writeTuple(buf *bytes.Buffer, this *Package, tup *Tuple, variadic bool, vis
 					if t, ok := typ.Underlying().(*Basic); !ok || t.kind != String {
 						panic("internal error: string type expected")
 					}
-					writeType(buf, this, typ, visited)
+					writeType(buf, typ, qf, visited)
 					buf.WriteString("...")
 					continue
 				}
 			}
-			writeType(buf, this, typ, visited)
+			writeType(buf, typ, qf, visited)
 		}
 	}
 	buf.WriteByte(')')
@@ -243,14 +269,14 @@ func writeTuple(buf *bytes.Buffer, this *Package, tup *Tuple, variadic bool, vis
 
 // WriteSignature writes the representation of the signature sig to buf,
 // without a leading "func" keyword.
-// Named types are printed package-qualified if they
-// do not belong to this package.
-func WriteSignature(buf *bytes.Buffer, this *Package, sig *Signature) {
-	writeSignature(buf, this, sig, make([]Type, 8))
+// The Qualifier controls the printing of
+// package-level objects, and may be nil.
+func WriteSignature(buf *bytes.Buffer, sig *Signature, qf Qualifier) {
+	writeSignature(buf, sig, qf, make([]Type, 8))
 }
 
-func writeSignature(buf *bytes.Buffer, this *Package, sig *Signature, visited []Type) {
-	writeTuple(buf, this, sig.params, sig.variadic, visited)
+func writeSignature(buf *bytes.Buffer, sig *Signature, qf Qualifier, visited []Type) {
+	writeTuple(buf, sig.params, sig.variadic, qf, visited)
 
 	n := sig.results.Len()
 	if n == 0 {
@@ -261,10 +287,10 @@ func writeSignature(buf *bytes.Buffer, this *Package, sig *Signature, visited []
 	buf.WriteByte(' ')
 	if n == 1 && sig.results.vars[0].name == "" {
 		// single unnamed result
-		writeType(buf, this, sig.results.vars[0].typ, visited)
+		writeType(buf, sig.results.vars[0].typ, qf, visited)
 		return
 	}
 
 	// multiple or named result(s)
-	writeTuple(buf, this, sig.results, false, visited)
+	writeTuple(buf, sig.results, false, qf, visited)
 }
diff --git a/src/go/types/typestring_test.go b/src/go/types/typestring_test.go
index 9945ed8c12..913e6c735c 100644
--- a/src/go/types/typestring_test.go
+++ b/src/go/types/typestring_test.go
@@ -154,7 +154,13 @@ func TestQualifiedTypeString(t *testing.T) {
 		{NewPointer(pT), p, "*T"},
 		{NewPointer(pT), q, "*p.T"},
 	} {
-		if got := TypeString(test.this, test.typ); got != test.want {
+		qualifier := func(pkg *Package) string {
+			if pkg != test.this {
+				return pkg.Name()
+			}
+			return ""
+		}
+		if got := TypeString(test.typ, qualifier); got != test.want {
 			t.Errorf("TypeString(%s, %s) = %s, want %s",
 				test.this, test.typ, got, test.want)
 		}