diff --git a/nac3artiq/src/lib.rs b/nac3artiq/src/lib.rs
index 18eeb5d..68e837b 100644
--- a/nac3artiq/src/lib.rs
+++ b/nac3artiq/src/lib.rs
@@ -660,7 +660,8 @@ impl Nac3 {
 
         let pass_options = PassBuilderOptions::create();
         pass_options.set_merge_functions(true);
-        let result = main.run_passes("default<O3>", &target_machine, pass_options);
+        let passes = format!("default<O{}>", self.llvm_options.opt_level as u32);
+        let result = main.run_passes(passes.as_str(), &target_machine, pass_options);
         if let Err(err) = result {
             panic!("Failed to run optimization for module `main`: {}", err.to_string());
         }
diff --git a/nac3core/src/codegen/mod.rs b/nac3core/src/codegen/mod.rs
index 4684cad..e05b721 100644
--- a/nac3core/src/codegen/mod.rs
+++ b/nac3core/src/codegen/mod.rs
@@ -327,7 +327,6 @@ impl WorkerRegistry {
             self.llvm_options.opt_level
         ).expect(format!("could not create target machine from properties {:?}", self.llvm_options.target).as_str());
         let passes = format!("default<O{}>", self.llvm_options.opt_level as u32);
-
         let result = module.run_passes(passes.as_str(), &target_machine, pass_options);
         if let Err(err) = result {
             panic!("Failed to run optimization for module `{}`: {}",
diff --git a/nac3standalone/src/main.rs b/nac3standalone/src/main.rs
index d45b875..16f3aae 100644
--- a/nac3standalone/src/main.rs
+++ b/nac3standalone/src/main.rs
@@ -370,7 +370,8 @@ fn main() {
 
     let pass_options = PassBuilderOptions::create();
     pass_options.set_merge_functions(true);
-    let result = main.run_passes("default<O3>", &target_machine, pass_options);
+    let passes = format!("default<O{}>", opt_level as u32);
+    let result = main.run_passes(passes.as_str(), &target_machine, pass_options);
     if let Err(err) = result {
         panic!("Failed to run optimization for module `main`: {}", err.to_string());
     }