diff --git a/tests/zwus.rs b/tests/zwus.rs
index 02047a4..ee510de 100644
--- a/tests/zwus.rs
+++ b/tests/zwus.rs
@@ -35,7 +35,7 @@ fn npm_vectors_decode_to_test123_checkmark() {
     //   zwus.encodeString("Test123!✅", 8)
     //
     // Keep these as raw strings to preserve invisible chars exactly.
-    let npm_base_3 = r#""#;
+    let npm_base_3 = r#"​᠎᠎​᠎­​᠎‍᠎‍­​​᠎‍​­​​᠎‍‍­​‍​​­​‍​‍­​‍‍᠎­​᠎‍᠎­​​​‍᠎᠎‍‍‍"#;
     let npm_base_6 = r#""#;
     let npm_base_8 = r#""#;