diff --git a/src/api/compile.rs b/src/api/compile.rs
index 750972e9..2250b641 100644
--- a/src/api/compile.rs
+++ b/src/api/compile.rs
@@ -201,7 +201,7 @@ impl Engine {
         scope: &Scope,
         scripts: impl AsRef<[S]>,
     ) -> ParseResult<AST> {
-        self.compile_with_scope_and_optimization_level(scope, scripts, self.optimization_level())
+        self.compile_with_scope_and_optimization_level(scope, scripts, self.optimization_level)
     }
     /// Join a list of strings and compile into an [`AST`] using own scope at a specific optimization level.
     ///
@@ -292,6 +292,6 @@ impl Engine {
 
         let mut peekable = stream.peekable();
         let mut state = ParseState::new(self, scope, tokenizer_control);
-        self.parse_global_expr(&mut peekable, &mut state, self.optimization_level())
+        self.parse_global_expr(&mut peekable, &mut state, self.optimization_level)
     }
 }
diff --git a/src/api/eval.rs b/src/api/eval.rs
index 65ef8c37..aec12d99 100644
--- a/src/api/eval.rs
+++ b/src/api/eval.rs
@@ -67,7 +67,7 @@ impl Engine {
         let ast = self.compile_with_scope_and_optimization_level(
             scope,
             &[script],
-            self.optimization_level(),
+            self.optimization_level,
         )?;
         self.eval_ast_with_scope(scope, &ast)
     }
diff --git a/src/api/run.rs b/src/api/run.rs
index 93a0a38b..673fa19e 100644
--- a/src/api/run.rs
+++ b/src/api/run.rs
@@ -26,11 +26,7 @@ impl Engine {
             self.lex_raw(&scripts, self.token_mapper.as_ref().map(Box::as_ref));
         let mut state = ParseState::new(self, scope, tokenizer_control);
 
-        let ast = self.parse(
-            &mut stream.peekable(),
-            &mut state,
-            self.optimization_level(),
-        )?;
+        let ast = self.parse(&mut stream.peekable(), &mut state, self.optimization_level)?;
 
         self.run_ast_with_scope(scope, &ast)
     }