diff --git a/tests/rust_functions/src/implementation.rs b/tests/rust_functions/src/implementation.rs
index 4f7fa62..a9db611 100644
--- a/tests/rust_functions/src/implementation.rs
+++ b/tests/rust_functions/src/implementation.rs
@@ -50,10 +50,10 @@ impl PersonTrait for Person {
     fn quote(&self, prefix: String, suffix: String) -> String {
         format!("{}{}{}", prefix, self.user_name, suffix)
     }
-    fn quote_bytes(&self, prefix: &[u8], suffix: &[u8]) -> String {
+    fn quote_bytes(&self, prefix: &[u8], suffix: &[u8]) -> Vec<u8> {
         let prefix = String::from_utf8_lossy(prefix);
         let suffix = String::from_utf8_lossy(suffix);
-        format!("{}{}{}", prefix, self.user_name, suffix)
+        format!("{}{}{}", prefix, self.user_name, suffix).into()
     }
 }
 
diff --git a/tests/rust_functions/src/interface.rs b/tests/rust_functions/src/interface.rs
index 68856da..7b69b5e 100644
--- a/tests/rust_functions/src/interface.rs
+++ b/tests/rust_functions/src/interface.rs
@@ -24,6 +24,9 @@ fn set_string_from_utf16(s: &mut String, str: *const c_ushort, len: c_int) {
 
 
 
+pub enum QByteArray {}
+
+
 fn to_usize(n: c_int) -> usize {
     if n < 0 {
         panic!("Cannot cast {} to usize", n);
@@ -71,7 +74,7 @@ pub trait PersonTrait {
     fn double_name(&mut self) -> ();
     fn greet(&self, name: String) -> String;
     fn quote(&self, prefix: String, suffix: String) -> String;
-    fn quote_bytes(&self, prefix: &[u8], suffix: &[u8]) -> String;
+    fn quote_bytes(&self, prefix: &[u8], suffix: &[u8]) -> Vec<u8>;
     fn vowels_in_name(&self) -> u8;
 }
 
@@ -152,7 +155,7 @@ pub extern "C" fn person_quote(ptr: *const Person, prefix_str: *const c_ushort,
 }
 
 #[no_mangle]
-pub extern "C" fn person_quote_bytes(ptr: *const Person, prefix_str: *const c_char, prefix_len: c_int, suffix_str: *const c_char, suffix_len: c_int, d: *mut QString, set: fn(*mut QString, str: *const c_char, len: c_int)) {
+pub extern "C" fn person_quote_bytes(ptr: *const Person, prefix_str: *const c_char, prefix_len: c_int, suffix_str: *const c_char, suffix_len: c_int, d: *mut QByteArray, set: fn(*mut QByteArray, str: *const c_char, len: c_int)) {
     let prefix = unsafe { slice::from_raw_parts(prefix_str as *const u8, to_usize(prefix_len)) };
     let suffix = unsafe { slice::from_raw_parts(suffix_str as *const u8, to_usize(suffix_len)) };
     let o = unsafe { &*ptr };
diff --git a/tests/test_functions.json b/tests/test_functions.json
index 6046bf7..9963757 100644
--- a/tests/test_functions.json
+++ b/tests/test_functions.json
@@ -61,7 +61,7 @@
                     ]
                 },
                 "quoteBytes": {
-                    "return": "QString",
+                    "return": "QByteArray",
                     "arguments": [
                         {
                             "name": "prefix",
diff --git a/tests/test_functions_rust.cpp b/tests/test_functions_rust.cpp
index 4e53979..03d82e1 100644
--- a/tests/test_functions_rust.cpp
+++ b/tests/test_functions_rust.cpp
@@ -7,6 +7,16 @@ namespace {
     void set_qstring(QString* val, const char* utf8, int nbytes) {
         *val = QString::fromUtf8(utf8, nbytes);
     }
+
+    typedef void (*qbytearray_set)(QByteArray* val, const char* bytes, int nbytes);
+    void set_qbytearray(QByteArray* v, const char* bytes, int nbytes) {
+        if (v->isNull() && nbytes == 0) {
+            *v = QByteArray(bytes, nbytes);
+        } else {
+            v->truncate(0);
+            v->append(bytes, nbytes);
+        }
+    }
     inline void personUserNameChanged(Person* o)
     {
         emit o->userNameChanged();
@@ -21,7 +31,7 @@ extern "C" {
     void person_double_name(Person::Private*);
     void person_greet(const Person::Private*, const ushort*, int, QString*, qstring_set);
     void person_quote(const Person::Private*, const ushort*, int, const ushort*, int, QString*, qstring_set);
-    void person_quote_bytes(const Person::Private*, const char*, int, const char*, int, QString*, qstring_set);
+    void person_quote_bytes(const Person::Private*, const char*, int, const char*, int, QByteArray*, qbytearray_set);
     quint8 person_vowels_in_name(const Person::Private*);
 };
 
@@ -74,10 +84,10 @@ QString Person::quote(const QString& prefix, const QString& suffix) const
     person_quote(m_d, prefix.utf16(), prefix.size(), suffix.utf16(), suffix.size(), &s, set_qstring);
     return s;
 }
-QString Person::quoteBytes(const QByteArray& prefix, const QByteArray& suffix) const
+QByteArray Person::quoteBytes(const QByteArray& prefix, const QByteArray& suffix) const
 {
-    QString s;
-    person_quote_bytes(m_d, prefix.data(), prefix.size(), suffix.data(), suffix.size(), &s, set_qstring);
+    QByteArray s;
+    person_quote_bytes(m_d, prefix.data(), prefix.size(), suffix.data(), suffix.size(), &s, set_qbytearray);
     return s;
 }
 quint8 Person::vowelsInName() const
diff --git a/tests/test_functions_rust.h b/tests/test_functions_rust.h
index fdf2945..f59aa7a 100644
--- a/tests/test_functions_rust.h
+++ b/tests/test_functions_rust.h
@@ -26,7 +26,7 @@ public:
     Q_INVOKABLE void doubleName();
     Q_INVOKABLE QString greet(const QString& name) const;
     Q_INVOKABLE QString quote(const QString& prefix, const QString& suffix) const;
-    Q_INVOKABLE QString quoteBytes(const QByteArray& prefix, const QByteArray& suffix) const;
+    Q_INVOKABLE QByteArray quoteBytes(const QByteArray& prefix, const QByteArray& suffix) const;
     Q_INVOKABLE quint8 vowelsInName() const;
 signals:
     void userNameChanged();