diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 12f49ac..ab73877 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -14,8 +14,8 @@ jobs:
       - uses: actions/checkout@v3.2.0
       - uses: erlef/setup-beam@v1.15.2
         with:
-          otp-version: "25.2"
-          gleam-version: "0.26.2"
+          otp-version: "26.0"
+          gleam-version: "0.34.1"
           rebar3-version: "3"
           # elixir-version: "1.14.2"
       - run: gleam format --check src test
diff --git a/gleam.toml b/gleam.toml
index 4fc516a..467675d 100644
--- a/gleam.toml
+++ b/gleam.toml
@@ -14,4 +14,4 @@ gleam_stdlib = "~> 0.31"
 gleam_json = "~> 0.5"
 
 [dev-dependencies]
-gleeunit = "~> 0.10"
+gleeunit = "~> 1.0"
diff --git a/manifest.toml b/manifest.toml
index 34be222..bfa9868 100644
--- a/manifest.toml
+++ b/manifest.toml
@@ -2,13 +2,13 @@
 # You typically do not need to edit this file
 
 packages = [
-  { name = "gleam_json", version = "0.6.0", build_tools = ["gleam"], requirements = ["gleam_stdlib", "thoas"], otp_app = "gleam_json", source = "hex", outer_checksum = "C6CC5BEECA525117E97D0905013AB3F8836537455645DDDD10FE31A511B195EF" },
-  { name = "gleam_stdlib", version = "0.31.0", build_tools = ["gleam"], requirements = [], otp_app = "gleam_stdlib", source = "hex", outer_checksum = "6D1BC5B4D4179B9FEE866B1E69FE180AC2CE485AD90047C0B32B2CA984052736" },
-  { name = "gleeunit", version = "0.11.0", build_tools = ["gleam"], requirements = ["gleam_stdlib"], otp_app = "gleeunit", source = "hex", outer_checksum = "1397E5C4AC4108769EE979939AC39BF7870659C5AFB714630DEEEE16B8272AD5" },
+  { name = "gleam_json", version = "0.7.0", build_tools = ["gleam"], requirements = ["thoas", "gleam_stdlib"], otp_app = "gleam_json", source = "hex", outer_checksum = "CB405BD93A8828BCD870463DE29375E7B2D252D9D124C109E5B618AAC00B86FC" },
+  { name = "gleam_stdlib", version = "0.35.1", build_tools = ["gleam"], requirements = [], otp_app = "gleam_stdlib", source = "hex", outer_checksum = "5443EEB74708454B65650FEBBB1EF5175057D1DEC62AEA9D7C6D96F41DA79152" },
+  { name = "gleeunit", version = "1.0.2", build_tools = ["gleam"], requirements = ["gleam_stdlib"], otp_app = "gleeunit", source = "hex", outer_checksum = "D364C87AFEB26BDB4FB8A5ABDE67D635DC9FA52D6AB68416044C35B096C6882D" },
   { name = "thoas", version = "0.4.1", build_tools = ["rebar3"], requirements = [], otp_app = "thoas", source = "hex", outer_checksum = "4918D50026C073C4AB1388437132C77A6F6F7C8AC43C60C13758CC0ADCE2134E" },
 ]
 
 [requirements]
 gleam_json = { version = "~> 0.5" }
 gleam_stdlib = { version = "~> 0.31" }
-gleeunit = { version = "~> 0.10" }
+gleeunit = { version = "~> 1.0" }
diff --git a/src/gleam_community/codec.gleam b/src/gleam_community/codec.gleam
index 711ab18..87b67d3 100644
--- a/src/gleam_community/codec.gleam
+++ b/src/gleam_community/codec.gleam
@@ -1,10 +1,12 @@
 // IMPORTS ---------------------------------------------------------------------
 
-import gleam/dynamic.{type DecodeError as DynamicError, DecodeError as DynamicError, type Dynamic}
+import gleam/dynamic.{
+  type DecodeError as DynamicError, type Dynamic, DecodeError as DynamicError,
+}
 import gleam/function
 import gleam/json.{type DecodeError as JsonError, type Json}
 import gleam/list
-import gleam/map.{type Map}
+import gleam/dict.{type Dict}
 import gleam/option.{type Option}
 import gleam/pair
 import gleam/result
@@ -32,7 +34,7 @@ import gleam/int
 ///
 /// Importantly, the codec API means our encoders and decoders stay _isomorphic_.
 /// That is, we can guarantee that the conversions to JSON and from `Dynamic` are
-/// always in sync. 
+/// always in sync.
 ///
 pub opaque type Codec(a) {
   Codec(
@@ -44,7 +46,7 @@ pub opaque type Codec(a) {
 ///
 ///
 pub opaque type Custom(a) {
-  Custom(encode: fn(a) -> Json, decode: Map(String, Decoder(a)))
+  Custom(encode: fn(a) -> Json, decode: Dict(String, Decoder(a)))
 }
 
 ///
@@ -125,23 +127,23 @@ pub fn optional(codec: Codec(a)) -> Codec(Option(a)) {
 
 ///
 ///
-pub fn object(codec: Codec(a)) -> Codec(Map(String, a)) {
-  let encode = fn(map) {
-    map
-    |> map.to_list
+pub fn object(codec: Codec(a)) -> Codec(Dict(String, a)) {
+  let encode = fn(dict) {
+    dict
+    |> dict.to_list
     |> list.map(pair.map_second(_, codec.encode))
     |> json.object
   }
-  let decode = dynamic.map(dynamic.string, codec.decode)
+  let decode = dynamic.dict(dynamic.string, codec.decode)
 
   Codec(encode, decode)
 }
 
 ///
 ///
-pub fn dictionary(key_codec: Codec(k), val_codec: Codec(v)) -> Codec(Map(k, v)) {
+pub fn dictionary(key_codec: Codec(k), val_codec: Codec(v)) -> Codec(Dict(k, v)) {
   list(tuple2(key_codec, val_codec))
-  |> map(map.to_list, map.from_list)
+  |> dict(dict.to_list, dict.from_list)
 }
 
 ///
@@ -194,18 +196,15 @@ pub fn tuple3(
 // CONSTRUCTORS: CUSTOM TYPES --------------------------------------------------
 
 pub fn custom(builder: Custom(a)) -> Codec(a) {
-  Codec(
-    encode: builder.encode,
-    decode: fn(dyn) {
-      let decode_tag = dynamic.field("$", dynamic.string)
-      use tag <- result.then(decode_tag(dyn))
+  Codec(encode: builder.encode, decode: fn(dyn) {
+    let decode_tag = dynamic.field("$", dynamic.string)
+    use tag <- result.then(decode_tag(dyn))
 
-      case map.get(builder.decode, tag) {
-        Ok(decoder) -> decoder(dyn)
-        Error(_) -> Error([DynamicError("Unknown tag", tag, ["$"])])
-      }
-    },
-  )
+    case dict.get(builder.decode, tag) {
+      Ok(decoder) -> decoder(dyn)
+      Error(_) -> Error([DynamicError("Unknown tag", tag, ["$"])])
+    }
+  })
 }
 
 pub opaque type Variant(a) {
@@ -241,7 +240,7 @@ pub fn make_variant(_: Int) -> List(Decoder(Dynamic)) {
 }
 
 pub fn make_custom(encode: fn(a) -> Json) -> Custom(a) {
-  Custom(encode, decode: map.new())
+  Custom(encode, decode: dict.new())
 }
 
 pub fn variant0(
@@ -253,7 +252,7 @@ pub fn variant0(
   let decoder = fn(_) { Ok(constructor) }
   let builder = builder(encoder)
 
-  Custom(..builder, decode: map.insert(builder.decode, tag, decoder))
+  Custom(..builder, decode: dict.insert(builder.decode, tag, decoder))
 }
 
 pub fn variant1(
@@ -268,7 +267,7 @@ pub fn variant1(
   let decoder = dynamic.decode1(constructor, dynamic.field("0", codec_a.decode))
   let builder = builder(encoder)
 
-  Custom(..builder, decode: map.insert(builder.decode, tag, decoder))
+  Custom(..builder, decode: dict.insert(builder.decode, tag, decoder))
 }
 
 pub fn variant2(
@@ -293,7 +292,7 @@ pub fn variant2(
     )
   let builder = builder(encoder)
 
-  Custom(..builder, decode: map.insert(builder.decode, tag, decoder))
+  Custom(..builder, decode: dict.insert(builder.decode, tag, decoder))
 }
 
 pub fn variant3(
@@ -321,7 +320,7 @@ pub fn variant3(
     )
   let builder = builder(encoder)
 
-  Custom(..builder, decode: map.insert(builder.decode, tag, decoder))
+  Custom(..builder, decode: dict.insert(builder.decode, tag, decoder))
 }
 
 pub fn variant4(
@@ -352,7 +351,7 @@ pub fn variant4(
     )
   let builder = builder(encoder)
 
-  Custom(..builder, decode: map.insert(builder.decode, tag, decoder))
+  Custom(..builder, decode: dict.insert(builder.decode, tag, decoder))
 }
 
 pub fn variant5(
@@ -386,7 +385,7 @@ pub fn variant5(
     )
   let builder = builder(encoder)
 
-  Custom(..builder, decode: map.insert(builder.decode, tag, decoder))
+  Custom(..builder, decode: dict.insert(builder.decode, tag, decoder))
 }
 
 pub fn variant6(
@@ -423,7 +422,7 @@ pub fn variant6(
     )
   let builder = builder(encoder)
 
-  Custom(..builder, decode: map.insert(builder.decode, tag, decoder))
+  Custom(..builder, decode: dict.insert(builder.decode, tag, decoder))
 }
 
 pub fn variant7(
@@ -463,7 +462,7 @@ pub fn variant7(
     )
   let builder = builder(encoder)
 
-  Custom(..builder, decode: map.insert(builder.decode, tag, decoder))
+  Custom(..builder, decode: dict.insert(builder.decode, tag, decoder))
 }
 
 pub fn variant8(
@@ -506,7 +505,7 @@ pub fn variant8(
     )
   let builder = builder(encoder)
 
-  Custom(..builder, decode: map.insert(builder.decode, tag, decoder))
+  Custom(..builder, decode: dict.insert(builder.decode, tag, decoder))
 }
 
 // QUERIES ---------------------------------------------------------------------
@@ -546,7 +545,7 @@ pub fn then(
 
 ///
 ///
-pub fn map(codec: Codec(a), from: fn(b) -> a, to: fn(a) -> b) -> Codec(b) {
+pub fn dict(codec: Codec(a), from: fn(b) -> a, to: fn(a) -> b) -> Codec(b) {
   use a <- then(codec, from)
   succeed(to(a))
 }
diff --git a/test/gleam_community_codec_test.gleam b/test/gleam_community_codec_test.gleam
index 782cf57..3759559 100644
--- a/test/gleam_community_codec_test.gleam
+++ b/test/gleam_community_codec_test.gleam
@@ -57,4 +57,4 @@ pub fn bool_test() {
   codec.encode_string(True, bool_codec)
   |> codec.decode_string(bool_codec)
   |> should.equal(Ok(True))
-}
\ No newline at end of file
+}