diff --git a/tests/attribute_doc_comments/expected.md b/tests/attribute_doc_comments/expected.md
index 7777b75..0bf24ed 100644
--- a/tests/attribute_doc_comments/expected.md
+++ b/tests/attribute_doc_comments/expected.md
@@ -15,7 +15,10 @@ pub mod trinitrix {
     pub enum Trinitrix {
         /// Attribute doc comment, but very ##" "## "# " escaped
         #[allow(non_camel_case_types)]
-        hi { trixy_output: trixy::oneshot::Sender<trixy::types::String>, name: String },
+        hi {
+            trixy_output: trixy::oneshot::Sender<trixy::types::String>,
+            name: trixy::types::newtypes::String,
+        },
     }
 }
 /* C API */
diff --git a/tests/doc_comments/expected.md b/tests/doc_comments/expected.md
index ff803d5..a985996 100644
--- a/tests/doc_comments/expected.md
+++ b/tests/doc_comments/expected.md
@@ -15,7 +15,10 @@ pub mod trinitrix {
     pub enum Trinitrix {
         /// Second doc comment
         #[allow(non_camel_case_types)]
-        hi { trixy_output: trixy::oneshot::Sender<trixy::types::String>, name: String },
+        hi {
+            trixy_output: trixy::oneshot::Sender<trixy::types::String>,
+            name: trixy::types::newtypes::String,
+        },
     }
 }
 /* C API */
diff --git a/tests/multi_line_doc_comment/expected.md b/tests/multi_line_doc_comment/expected.md
index 3544702..4dd53cf 100644
--- a/tests/multi_line_doc_comment/expected.md
+++ b/tests/multi_line_doc_comment/expected.md
@@ -18,7 +18,10 @@ pub mod trinitrix {
     pub enum Trinitrix {
         ///I \n also \n contain \n them
         #[allow(non_camel_case_types)]
-        hi { trixy_output: trixy::oneshot::Sender<trixy::types::String>, name: String },
+        hi {
+            trixy_output: trixy::oneshot::Sender<trixy::types::String>,
+            name: trixy::types::newtypes::String,
+        },
     }
 }
 /* C API */
diff --git a/tests/trinitrix_api/expected.md b/tests/trinitrix_api/expected.md
index 5d50051..97101a3 100644
--- a/tests/trinitrix_api/expected.md
+++ b/tests/trinitrix_api/expected.md
@@ -34,7 +34,7 @@ pub mod trinitrix {
             /// Send a message to the current room
             /// The send message is interpreted literally.
             #[allow(non_camel_case_types)]
-            room_message_send { message: String },
+            room_message_send { message: trixy::types::newtypes::String },
             Ui(ui::Ui),
             Keymaps(keymaps::Keymaps),
             Raw(raw::Raw),
@@ -105,15 +105,22 @@ pub mod trinitrix {
             pub enum Keymaps {
                 /// Add a new keymapping
                 #[allow(non_camel_case_types)]
-                add { mode: String, key: String, callback: extern "C" fn() },
+                add {
+                    mode: trixy::types::newtypes::String,
+                    key: trixy::types::newtypes::String,
+                    callback: extern "C" fn(),
+                },
                 /// Remove a keymapping
                 ///
                 /// Does nothing, if the keymapping doesn't exists yet
                 #[allow(non_camel_case_types)]
-                remove { mode: String, key: String },
+                remove {
+                    mode: trixy::types::newtypes::String,
+                    key: trixy::types::newtypes::String,
+                },
                 /// List declared keymappings
                 #[allow(non_camel_case_types)]
-                get { mode: String },
+                get { mode: trixy::types::newtypes::String },
             }
         }
         /// Functions only used internally within Trinitrix
@@ -122,17 +129,17 @@ pub mod trinitrix {
             pub enum Raw {
                 /// Send an error to the default error output
                 #[allow(non_camel_case_types)]
-                raise_error { error_message: String },
+                raise_error { error_message: trixy::types::newtypes::String },
                 /// Send output to the default output
                 /// This is mainly used to display the final
                 /// output of evaluated lua commands.
                 #[allow(non_camel_case_types)]
-                display_output { output_message: String },
+                display_output { output_message: trixy::types::newtypes::String },
                 /// Input a character without checking for possible keymaps
                 /// If the current state does not expect input, this character is ignored
                 /// The encoding is the same as in the `trinitrix.api.keymaps` commands
                 #[allow(non_camel_case_types)]
-                send_input_unprocessed { input: String },
+                send_input_unprocessed { input: trixy::types::newtypes::String },
                 Private(__private::Private),
             }
             /// This namespace is used to store some command specific data (like functions, as