diff --git a/importer/importer.go b/importer/importer.go
index 099dadd48..ec5aafaea 100644
--- a/importer/importer.go
+++ b/importer/importer.go
@@ -17,15 +17,15 @@ import (
 
 // An Importer's methods are not thread-safe.
 type Importer struct {
-	context  *Context                // the client context
+	config   *Config                 // the client configuration
 	Fset     *token.FileSet          // position info for all files seen
 	Packages map[string]*PackageInfo // keys are import paths
 	errors   map[string]error        // cache of errors by import path
 }
 
-// Context specifies the supporting context for the importer.
+// Config specifies the configuration for the importer.
 //
-type Context struct {
+type Config struct {
 	// TypeChecker contains options relating to the type checker.
 	// The Importer will override any user-supplied values for its
 	// Expr, Ident, ImplicitObj and Import fields; other fields
@@ -59,16 +59,16 @@ type Context struct {
 type SourceLoader func(fset *token.FileSet, path string) (files []*ast.File, err error)
 
 // New returns a new, empty Importer using configuration options
-// specified by context.
+// specified by config.
 //
-func New(context *Context) *Importer {
+func New(config *Config) *Importer {
 	imp := &Importer{
-		context:  context,
+		config:   config,
 		Fset:     token.NewFileSet(),
 		Packages: make(map[string]*PackageInfo),
 		errors:   make(map[string]error),
 	}
-	imp.context.TypeChecker.Import = imp.doImport
+	imp.config.TypeChecker.Import = imp.doImport
 	return imp
 }
 
@@ -95,7 +95,7 @@ func (imp *Importer) doImport(imports map[string]*types.Package, path string) (p
 	// a PackageInfo and update our map (imp.Packages) and the
 	// type-checker's map (imports).
 	var info *PackageInfo
-	if imp.context.Loader != nil {
+	if imp.config.Loader != nil {
 		info, err = imp.LoadPackage(path)
 	} else if pkg, err = types.GcImport(imports, path); err == nil {
 		info = &PackageInfo{Pkg: pkg}
@@ -119,15 +119,17 @@ func (imp *Importer) doImport(imports map[string]*types.Package, path string) (p
 // PackageInfo.
 //
 // Not idempotent!
-// Precondition: Importer.context.Loader != nil.
+// Precondition: Importer.config.Loader != nil.
+// TODO(adonovan): fix: violated in call from CreatePackageFromArgs!
 // Not thread-safe!
 // TODO(adonovan): rethink this API.
 //
+//
 func (imp *Importer) LoadPackage(importPath string) (*PackageInfo, error) {
-	if imp.context.Loader == nil {
+	if imp.config.Loader == nil {
 		panic("Importer.LoadPackage without a SourceLoader")
 	}
-	files, err := imp.context.Loader(imp.Fset, importPath)
+	files, err := imp.config.Loader(imp.Fset, importPath)
 	if err != nil {
 		return nil, err
 	}
@@ -163,7 +165,7 @@ func (imp *Importer) CreateSourcePackage(importPath string, files []*ast.File) *
 			Implicits: make(map[ast.Node]types.Object),
 		},
 	}
-	pkgInfo.Pkg, pkgInfo.Err = imp.context.TypeChecker.Check(importPath, imp.Fset, files, &pkgInfo.Info)
+	pkgInfo.Pkg, pkgInfo.Err = imp.config.TypeChecker.Check(importPath, imp.Fset, files, &pkgInfo.Info)
 	imp.Packages[importPath] = pkgInfo
 	return pkgInfo
 }
diff --git a/importer/source_test.go b/importer/source_test.go
index 821d18880..3be56cd7a 100644
--- a/importer/source_test.go
+++ b/importer/source_test.go
@@ -235,7 +235,7 @@ func TestEnclosingFunction(t *testing.T) {
 			"900", "func@2.27"},
 	}
 	for _, test := range tests {
-		imp := importer.New(new(importer.Context)) // (NB: no Loader)
+		imp := importer.New(new(importer.Config)) // (NB: no Loader)
 		f, start, end := findInterval(t, imp.Fset, test.input, test.substr)
 		if f == nil {
 			continue
diff --git a/ssa/builder_test.go b/ssa/builder_test.go
index 98cd2f60e..e33f81da6 100644
--- a/ssa/builder_test.go
+++ b/ssa/builder_test.go
@@ -34,7 +34,7 @@ func main() {
         w.Write(nil)    // interface invoke of external declared method
 }
 `
-	imp := importer.New(new(importer.Context)) // no Loader; uses GC importer
+	imp := importer.New(new(importer.Config)) // no Loader; uses GC importer
 
 	f, err := parser.ParseFile(imp.Fset, "<input>", test, parser.DeclarationErrors)
 	if err != nil {
diff --git a/ssa/example_test.go b/ssa/example_test.go
index b6c96d995..48fa8237f 100644
--- a/ssa/example_test.go
+++ b/ssa/example_test.go
@@ -37,7 +37,7 @@ func main() {
 }
 `
 	// Construct an importer.  Imports will be loaded as if by 'go build'.
-	imp := importer.New(&importer.Context{Loader: importer.MakeGoBuildLoader(nil)})
+	imp := importer.New(&importer.Config{Loader: importer.MakeGoBuildLoader(nil)})
 
 	// Parse the input file.
 	file, err := parser.ParseFile(imp.Fset, "hello.go", hello, parser.DeclarationErrors)
diff --git a/ssa/interp/interp_test.go b/ssa/interp/interp_test.go
index 12d1cb6fe..553ae679e 100644
--- a/ssa/interp/interp_test.go
+++ b/ssa/interp/interp_test.go
@@ -146,10 +146,9 @@ func run(t *testing.T, dir, input string) bool {
 		inputs = append(inputs, dir+i)
 	}
 
-	impctx := &importer.Context{
+	imp := importer.New(&importer.Config{
 		Loader: importer.MakeGoBuildLoader(nil),
-	}
-	imp := importer.New(impctx)
+	})
 	files, err := importer.ParseFiles(imp.Fset, ".", inputs...)
 	if err != nil {
 		t.Errorf("ssa.ParseFiles(%s) failed: %s", inputs, err.Error())
diff --git a/ssa/source_test.go b/ssa/source_test.go
index 9bc07662c..3af1fd99c 100644
--- a/ssa/source_test.go
+++ b/ssa/source_test.go
@@ -17,7 +17,7 @@ import (
 )
 
 func TestObjValueLookup(t *testing.T) {
-	imp := importer.New(new(importer.Context)) // (uses GCImporter)
+	imp := importer.New(new(importer.Config)) // (uses GCImporter)
 	f, err := parser.ParseFile(imp.Fset, "testdata/objlookup.go", nil, parser.DeclarationErrors|parser.ParseComments)
 	if err != nil {
 		t.Errorf("parse error: %s", err)