diff --git a/regexp.py b/regexp.py
--- a/regexp.py
+++ b/regexp.py
@@ -92,6 +92,10 @@ class Chain(Token):
 			else:
 				previous = [token]
 
+	@property
+	def is_skippable(self):
+		return all(x.is_skippable for x in self.content)
+
 	def __str__(self):
 		return "(" + "".join(str(x) for x in self.content) + ")"
 
@@ -159,6 +163,8 @@ class Regexp:
 			rules[key].add(j)
 
 		end_states = set(r.list_last())
+		if r.is_skippable:
+			end_states.add(-1)
 
 		return rules, end_states
 
@@ -177,7 +183,7 @@ class Regexp:
 
 
 if __name__ == "__main__":
-	tests = ["a", "ab", "aabb", "abab", "abcd", "abcbcdbcd"]
+	tests = ["", "a", "ab", "aabb", "abab", "abcd", "abcbcdbcd"]
 	for pattern in ["a*b*", "a+b+", "(ab)*", "(ab)+", "a((bc)*d)*"]:
 		print("#", pattern)
 		r = Regexp(pattern)