diff --git a/tests/test_regexp.rs b/tests/test_regexp.rs
--- a/tests/test_regexp.rs
+++ b/tests/test_regexp.rs
@@ -51,24 +51,6 @@ fn test_eval_asterisk_dfa() {
 }
 
 #[test]
-fn test_eval_plus_nfa() {
-	let r = Regexp::new(&String::from("(ab)+")).unwrap();
-	assert!(!r.eval(String::from("a")));
-	assert!(r.eval(String::from("ab")));
-	assert!(r.eval(String::from("abab")));
-	assert!(!r.eval(String::from("aabb")));
-}
-
-#[test]
-fn test_eval_plus_dfa() {
-	let r = Regexp::new(&String::from("(ab)+")).unwrap().determinize();
-	assert!(!r.eval(String::from("a")));
-	assert!(r.eval(String::from("ab")));
-	assert!(r.eval(String::from("abab")));
-	assert!(!r.eval(String::from("aabb")));
-}
-
-#[test]
 fn test_eval_alternative_nfa() {
 	let r = Regexp::new(&String::from("a|b|c")).unwrap();
 	assert!(r.eval(String::from("a")));
@@ -121,12 +103,6 @@ fn test_invalid_asterisk() {
 }
 
 #[test]
-fn test_invalid_plus() {
-	let x = Regexp::new(&String::from("+"));
-	assert!(matches!(x, Err(ParsingError::Plus{s: _, pos: 0})));
-}
-
-#[test]
 fn test_invalid_closing_parenthesis() {
 	let x = Regexp::new(&String::from("(a"));
 	assert!(matches!(x, Err(ParsingError::ClosingParenthesis{s: _, pos: 0})));