diff --git a/stdlib/src/parallel.rs b/stdlib/src/parallel.rs
index e5f4eaeb..58acf880 100644
--- a/stdlib/src/parallel.rs
+++ b/stdlib/src/parallel.rs
@@ -1,64 +1,82 @@
 use crate::{StdFunction, StdlibModule, StdlibRegistry};
-use std::cell::RefCell;
 use std::collections::HashMap;
 use std::rc::Rc;
 use std::thread;
-use techscript_runtime::{error::RuntimeError, value::RuntimeValue};
+use techscript_runtime::{function::Callable, value::RuntimeValue};
 
-impl StdlibRegistry {
-    pub fn register_parallel(&mut self) {
-        let mut exports: HashMap<String, Rc<dyn techscript_runtime::function::Callable>> =
-            HashMap::new();
+fn fn_run() -> StdFunction {
+    StdFunction {
+        name: "run".to_string(),
+        arity: 1,
+        callback: |_ctx, args| {
+            let _task = args[0].to_string();
+            thread::spawn(move || {});
+            Ok(RuntimeValue::Null)
+        },
+    }
+}
 
-        exports.insert(
-            "run".to_string(),
-            Rc::new(StdFunction {
-                name: "run".to_string(),
-                arity: 1,
-                callback: |_ctx, args| {
-                    let _task = args[0].to_string();
-                    thread::spawn(move || {});
-                    Ok(RuntimeValue::Null)
-                },
-            }),
-        );
+fn fn_sleep() -> StdFunction {
+    StdFunction {
+        name: "sleep".to_string(),
+        arity: 1,
+        callback: |_ctx, args| {
+            let ms = args[0].try_into_int().unwrap_or(0) as u64;
+            thread::sleep(std::time::Duration::from_millis(ms));
+            Ok(RuntimeValue::Null)
+        },
+    }
+}
 
-        exports.insert(
-            "sleep".to_string(),
-            Rc::new(StdFunction {
-                name: "sleep".to_string(),
-                arity: 1,
-                callback: |_ctx, args| {
-                    let ms = args[0].try_into_int().unwrap_or(0) as u64;
-                    thread::sleep(std::time::Duration::from_millis(ms));
-                    Ok(RuntimeValue::Null)
-                },
-            }),
-        );
+fn fn_num_cpus() -> StdFunction {
+    StdFunction {
+        name: "num_cpus".to_string(),
+        arity: 0,
+        callback: |_ctx, _args| {
+            Ok(RuntimeValue::Int(
+                std::thread::available_parallelism()
+                    .map(|n| n.get() as i64)
+                    .unwrap_or(1),
+            ))
+        },
+    }
+}
 
-        exports.insert(
-            "num_cpus".to_string(),
-            Rc::new(StdFunction {
-                name: "num_cpus".to_string(),
-                arity: 0,
-                callback: |_ctx, _args| {
-                    Ok(RuntimeValue::Int(
-                        std::thread::available_parallelism()
-                            .map(|n| n.get() as i64)
-                            .unwrap_or(1),
-                    ))
-                },
-            }),
-        );
+fn create_parallel_exports() -> HashMap<String, Rc<dyn Callable>> {
+    let mut exports: HashMap<String, Rc<dyn Callable>> = HashMap::new();
+    exports.insert("run".to_string(), Rc::new(fn_run()));
+    exports.insert("sleep".to_string(), Rc::new(fn_sleep()));
+    exports.insert("num_cpus".to_string(), Rc::new(fn_num_cpus()));
+    exports
+}
 
+impl StdlibRegistry {
+    pub fn register_parallel(&mut self) {
         self.register_module(
             "std.parallel",
             StdlibModule {
                 name: "std.parallel".to_string(),
                 version: "1.0.0".to_string(),
-                exports,
+                exports: create_parallel_exports(),
                 required_capabilities: Vec::new(),
             },
         );
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_register_parallel() {
+        let mut registry = StdlibRegistry::new();
+        registry.register_parallel();
+        assert!(registry.get_module("std.parallel").is_some());
+
+        let module = registry.get_module("std.parallel").unwrap();
+        assert!(module.exports.contains_key("run"));
+        assert!(module.exports.contains_key("sleep"));
+        assert!(module.exports.contains_key("num_cpus"));
+    }
+}