diff --git a/src/lexer.rs b/src/lexer.rs
index 9e60666..eff3350 100644
--- a/src/lexer.rs
+++ b/src/lexer.rs
@@ -12,7 +12,6 @@ use crate::FunctionIdentifier::{Cbrt, Ceil, Cos, Exp, Abs, Floor, Ln, Log, Round
 use crate::units::Unit;
 use crate::units::Unit::*;
 use unicode_segmentation::{Graphemes, UnicodeSegmentation};
-use std::cmp::Ordering;
 
 fn is_word_char_str(input: &str) -> bool {
   matches!(input, "A" | "B" | "C" | "D" | "E" | "F" | "G" | "H" | "I" | "J" | "K" | "L"
@@ -625,19 +624,15 @@ pub fn lex(input: &str, remove_trailing_operator: bool, default_degree: Unit) ->
   }
   let tokens = &mut lexer.tokens;
   // auto insert missing parentheses in first and last position
-  match lexer.left_paren_count.cmp(&lexer.right_paren_count) {
-    Ordering::Less => {
-      let missing_left_parens = lexer.right_paren_count - lexer.left_paren_count;
-      for _ in 0..missing_left_parens {
-        tokens.insert(0, Token::Operator(LeftParen));
-      }
+  if lexer.left_paren_count > lexer.right_paren_count {
+    let missing_right_parens = lexer.left_paren_count - lexer.right_paren_count;
+    for _ in 0..missing_right_parens {
+      tokens.push(Token::Operator(RightParen));
     }
-    Ordering::Equal => {}
-    Ordering::Greater => {
-      let missing_right_parens = lexer.left_paren_count - lexer.right_paren_count;
-      for _ in 0..missing_right_parens {
-        tokens.push(Token::Operator(RightParen));
-      }
+  } else if lexer.left_paren_count < lexer.right_paren_count {
+    let missing_left_parens = lexer.right_paren_count - lexer.left_paren_count;
+    for _ in 0..missing_left_parens {
+      tokens.insert(0, Token::Operator(LeftParen));
     }
   }