diff --git a/go/loader/backdoor.go b/go/loader/backdoor.go
new file mode 100644
index 00000000..1a5803b2
--- /dev/null
+++ b/go/loader/backdoor.go
@@ -0,0 +1,13 @@
+package loader
+
+import (
+	"go/ast"
+	"go/build"
+	"go/token"
+)
+
+// PackageLocatorFunc exposes the address of parsePackageFiles to tests.
+// This is a temporary hack until we expose a proper PackageLocator interface.
+func PackageLocatorFunc() *func(ctxt *build.Context, fset *token.FileSet, path string, which string) ([]*ast.File, error) {
+	return &parsePackageFiles
+}