diff --git a/rpc-toolkit-macro-internals/src/command/build.rs b/rpc-toolkit-macro-internals/src/command/build.rs
index 3f5c5ea..477c790 100644
--- a/rpc-toolkit-macro-internals/src/command/build.rs
+++ b/rpc-toolkit-macro-internals/src/command/build.rs
@@ -796,10 +796,6 @@ fn cli_handler(
                     .unwrap_or_else(|| LitStr::new(&name.to_string(), name.span()));
                 let field_name = Ident::new(&format!("arg_{}", name), name.span());
                 let ty = arg.ty.clone();
-                let mut ty = quote! { #ty };
-                if arg.default.is_some() && !arg.optional {
-                    ty = quote! { Option<#ty> };
-                }
                 arg_def.push(quote! {
                     #[serde(rename = #rename)]
                     #field_name: #ty,
@@ -849,7 +845,7 @@ fn cli_handler(
                         ::rpc_toolkit::command_helpers::prelude::default_arg_parser(arg_val, matches)
                     }
                 };
-                if arg.optional || arg.default.is_some() {
+                if arg.optional {
                     quote! {
                         #field_name: if let Some(arg_val) = matches.value_of(#arg_name) {
                             Some(#parse_val?)
@@ -857,6 +853,28 @@ fn cli_handler(
                             None
                         },
                     }
+                } else if let Some(default) = &arg.default {
+                    if let Some(default) = default {
+                        let path: Path = match syn::parse_str(&default.value()) {
+                            Ok(a) => a,
+                            Err(e) => return e.into_compile_error(),
+                        };
+                        quote! {
+                            #field_name: if let Some(arg_val) = matches.value_of(#arg_name) {
+                                #parse_val?
+                            } else {
+                                #path()
+                            },
+                        }
+                    } else {
+                        quote! {
+                            #field_name: if let Some(arg_val) = matches.value_of(#arg_name) {
+                                #parse_val?
+                            } else {
+                                Default::default()
+                            },
+                        }
+                    }
                 } else if arg.multiple.is_some() {
                     quote! {
                         #field_name: matches.values_of(#arg_name).iter().flatten().map(|arg_val| #parse_val).collect::<Result<_, _>>()?,
diff --git a/rpc-toolkit/tests/test.rs b/rpc-toolkit/tests/test.rs
index 9991c0b..c3d59b1 100644
--- a/rpc-toolkit/tests/test.rs
+++ b/rpc-toolkit/tests/test.rs
@@ -42,6 +42,10 @@ impl Context for AppState {
     }
 }
 
+fn test_string() -> String {
+    "test".to_owned()
+}
+
 #[command(
     about = "Does the thing",
     subcommands("dothething2::<U, E>", self(dothething_impl(async)))
@@ -52,7 +56,7 @@ async fn dothething<
 >(
     #[context] _ctx: AppState,
     #[arg(short = 'a')] arg1: Option<String>,
-    #[arg(short = 'b')] val: String,
+    #[arg(short = 'b', default = "test_string")] val: String,
     #[arg(short = 'c', help = "I am the flag `c`!", default)] arg3: bool,
     #[arg(stdin)] structured: U,
 ) -> Result<(Option<String>, String, bool, U), RpcError> {
@@ -147,8 +151,8 @@ async fn test_rpc() {
         .arg("--exact")
         .arg("--nocapture")
         .arg("--")
-        .arg("-b")
-        .arg("test")
+        // .arg("-b")
+        // .arg("test")
         .arg("dothething2")
         .stdin(std::process::Stdio::piped())
         .stdout(std::process::Stdio::piped())