diff --git a/src/parz/combinators.gleam b/src/parz/combinators.gleam
index b6556a8..9bfd626 100644
--- a/src/parz/combinators.gleam
+++ b/src/parz/combinators.gleam
@@ -122,19 +122,8 @@ pub fn many(parser: Parser(a)) {
   }
 }
 
-pub fn concat(parser: Parser(List(a)), merge) {
-  fn(input) {
-    case parser(input) {
-      Error(err) -> Error(err)
-      Ok(ok) -> {
-        Ok(ParserState(merge(ok.matched), ok.remaining))
-      }
-    }
-  }
-}
-
 pub fn concat_str(parser) {
-  concat(parser, string.concat)
+  map(parser, string.concat)
 }
 
 pub fn label_error(parser, message) {
diff --git a/test/combinators_test.gleam b/test/combinators_test.gleam
index c3ddb3d..dcdea84 100644
--- a/test/combinators_test.gleam
+++ b/test/combinators_test.gleam
@@ -1,8 +1,8 @@
 import gleeunit/should
 import parz.{run}
 import parz/combinators.{
-  between, choice, concat, concat_str, label_error, left, many, many1, map,
-  maybe, right, sequence,
+  between, choice, concat_str, label_error, left, many, many1, map, maybe, right,
+  sequence,
 }
 import parz/parsers.{letters, str}
 import parz/types.{ParserState}
@@ -132,7 +132,7 @@ pub fn sequence_test() {
   |> should.be_error
 }
 
-pub fn concat_test() {
+pub fn concat_str_test() {
   let parser = concat_str(sequence([str("["), letters(), str("]")]))
 
   run(parser, "[hello]")