Index: cmd/llgoi/llgoi.go
===================================================================
--- cmd/llgoi/llgoi.go
+++ cmd/llgoi/llgoi.go
@@ -76,8 +76,8 @@
 	imports []*types.Package
 	scope   map[string]types.Object
 
-	pkgmap, inputPkgmap map[string]*types.Package
-	pkgnum              int
+	pkgmap map[string]*types.Package
+	pkgnum int
 }
 
 func (in *interp) makeCompilerOptions() error {
@@ -91,6 +91,7 @@
 		TargetTriple:  llvm.DefaultTargetTriple(),
 		ImportPaths:   importPaths,
 		GenerateDebug: true,
+		Packages:      in.pkgmap,
 	}
 	err = in.copts.MakeImporter()
 	if err != nil {
@@ -99,9 +100,6 @@
 
 	origImporter := in.copts.Importer
 	in.copts.Importer = func(pkgmap map[string]*types.Package, pkgpath string) (*types.Package, error) {
-		if pkg, ok := in.inputPkgmap[pkgpath]; ok {
-			return pkg, nil
-		}
 		if pkg, ok := pkgmap[pkgpath]; ok && pkg.Complete() {
 			return pkg, nil
 		}
@@ -113,7 +111,6 @@
 func (in *interp) init() error {
 	in.scope = make(map[string]types.Object)
 	in.pkgmap = make(map[string]*types.Package)
-	in.inputPkgmap = make(map[string]*types.Package)
 
 	err := in.makeCompilerOptions()
 	if err != nil {
@@ -174,7 +171,7 @@
 		}
 	}()
 	importfunc()
-	in.inputPkgmap[pkgpath] = pkg
+	in.pkgmap[pkgpath] = pkg
 	return
 }
 
Index: irgen/compiler.go
===================================================================
--- irgen/compiler.go
+++ irgen/compiler.go
@@ -102,6 +102,9 @@
 	// DisableUnusedImportCheck disables the unused import check performed
 	// by go/types if set to true.
 	DisableUnusedImportCheck bool
+
+	// Packages is used by go/types as the imported package map if non-nil.
+	Packages map[string]*types.Package
 }
 
 type Compiler struct {
@@ -208,8 +211,9 @@
 	impcfg := &loader.Config{
 		Fset: fset,
 		TypeChecker: types.Config{
-			Import: compiler.Importer,
-			Sizes:  compiler.llvmtypes,
+			Packages: compiler.Packages,
+			Import:   compiler.Importer,
+			Sizes:    compiler.llvmtypes,
 			DisableUnusedImportCheck: compiler.DisableUnusedImportCheck,
 		},
 		Build:          &buildctx.Context,
Index: test/llgoi/import-source.test
===================================================================
--- test/llgoi/import-source.test
+++ test/llgoi/import-source.test
@@ -1,4 +1,4 @@
-// RUN: env GOPATH=%S/Inputs llgoi < %s | FileCheck %s
+// RUN: env GOPATH=%S/Inputs llgoi < %s 2>&1 | FileCheck %s
 
 // make sure user symbols do not conflict with imported source package
 Answer := 1
@@ -16,5 +16,15 @@
 strconv.FormatBool(true)
 // CHECK: #0 string = true
 
+var v1 strconv.NumError
+var v2 strconv.NumError
+
+// v1 and v2 should have the same type identity.
+// CHECK-NOT: cannot assign
+v1 = v2
+
+// Method lookup relies on v1 having a consistent type.
+v1.Error
+
 import "foo_cgo"
 // CHECK: foo_cgo: cannot load cgo package