diff --git a/cue/load/config.go b/cue/load/config.go
index 073ae5c4a..d79e9fa3e 100644
--- a/cue/load/config.go
+++ b/cue/load/config.go
@@ -252,7 +252,7 @@ type Config struct {
 	DataFiles bool
 
 	// StdRoot specifies an alternative directory for standard libraries.
-	// This is mostly used for bootstrapping.
+	// Deprecated: this has no effect.
 	StdRoot string
 
 	// ParseFile is called to read and parse each file when preparing a
@@ -310,6 +310,7 @@ type fsPath string
 
 func addImportQualifier(pkg importPath, name string) (importPath, errors.Error) {
 	if name != "" {
+		// TODO use module.ParseImportPath
 		s := string(pkg)
 		if i := strings.LastIndexByte(s, '/'); i >= 0 {
 			s = s[i+1:]
diff --git a/cue/load/import.go b/cue/load/import.go
index e074c2b6e..8524e2249 100644
--- a/cue/load/import.go
+++ b/cue/load/import.go
@@ -213,13 +213,8 @@ func (l *loader) _loadFunc(pos token.Pos, path string) *build.Instance {
 		return l.cfg.newErrInstance(errors.Newf(pos, "relative import paths not allowed (%q)", path))
 	}
 
-	// is it a builtin?
-	if strings.IndexByte(strings.Split(path, "/")[0], '.') == -1 {
-		if l.cfg.StdRoot != "" {
-			p := l.newInstance(pos, impPath)
-			_ = l.importPkg(pos, p)
-			return p
-		}
+	if isStdlibPackage(path) {
+		// It looks like a builtin.
 		return nil
 	}
 
@@ -408,3 +403,10 @@ func absPathForSourceLoc(loc module.SourceLoc) (string, error) {
 	}
 	return filepath.Join(osPath, loc.Dir), nil
 }
+
+// isStdlibPackage reports whether pkgPath looks like
+// an import from the standard library.
+func isStdlibPackage(pkgPath string) bool {
+	firstElem, _, _ := strings.Cut(pkgPath, "/")
+	return strings.IndexByte(firstElem, '.') == -1
+}