diff --git a/android/util.go b/android/util.go
index fb09128..08a3521 100644
--- a/android/util.go
+++ b/android/util.go
@@ -26,7 +26,11 @@
 
 // CopyOf returns a new slice that has the same contents as s.
 func CopyOf(s []string) []string {
-	return append([]string(nil), s...)
+	// If the input is nil, return nil and not an empty list
+	if s == nil {
+		return s
+	}
+	return append([]string{}, s...)
 }
 
 // Concat returns a new slice concatenated from the two input slices. It does not change the input