diff --git a/src/jit/engine.rs b/src/jit/engine.rs
index b2a6dc5..9327071 100644
--- a/src/jit/engine.rs
+++ b/src/jit/engine.rs
@@ -52,7 +52,7 @@ impl Engine {
     pub fn translate(&mut self, fn_impl: &ast::FnImpl) -> Result<(), String> {
         let int = self.module.target_config().pointer_type();
         let builder = FunctionBuilder::new(&mut self.ctx.func, &mut self.builder_context);
-        let mut trans = super::translate::FunctionTranslator { int, builder };
+        let trans = super::translate::FunctionTranslator { int, builder };
         trans.translate(fn_impl);
         Ok(())
     }
@@ -62,19 +62,26 @@ impl Engine {
 mod tests {
     use super::*;
 
-    #[test]
-    fn simple_math() {
+    fn jit_compile(source: &str) -> *const u8 {
         use crate::parse::lexer::Lexer;
         use crate::parse::rd::RecursiveDescent;
-        let source = "simple_math() i64 { (1 + 2) * (3 / (4 + 5)) }";
         println!("JIT-compiling source: {}", source);
         let lexer = Lexer::new(source);
         let mut rd = RecursiveDescent::new(lexer);
         let def = rd.build_fn(false, None);
         if let ast::Definition::Function { implementation, .. } = def {
-            Engine::new().compile(&implementation).unwrap();
+            Engine::new().compile(&implementation).unwrap()
         } else {
             panic!("Failed to parse function from test source");
         }
+
+    } 
+
+    #[test]
+    fn simple_math() {
+        let source = "simple_math() i64 { (1 + 2) * ((4 + 5) / 3) }";
+        let code_ptr = jit_compile(source);
+        let code_fn = unsafe { std::mem::transmute::<_, fn() -> i64>(code_ptr) };
+        assert_eq!(code_fn(), 9);
     }
 }