diff --git a/.github/actions/test/action.yml b/.github/actions/test/action.yml
index 84db130..69b1ca4 100644
--- a/.github/actions/test/action.yml
+++ b/.github/actions/test/action.yml
@@ -9,7 +9,7 @@ inputs:
   erlang-version:
     description: erlang-otp version
     required: false
-    default: 25.0.2
+    default: 26.2.2
   node-version:
     description: nodeJS version
     required: false
diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 24d55cc..081d467 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -7,8 +7,8 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        erlang: ["25.3.2.3", "26.0.2"]
-        gleam: ["0.34.1"]
+        erlang: ["25.3.2.3", "26.2.2"]
+        gleam: ["0.34.1","1.0.0-rc1"]
     steps:
       - uses: actions/checkout@v2
       - uses: ./.github/actions/test
diff --git a/.github/workflows/release.yaml b/.github/workflows/release.yaml
index 770b174..7c9f91d 100644
--- a/.github/workflows/release.yaml
+++ b/.github/workflows/release.yaml
@@ -20,7 +20,7 @@ jobs:
       - uses: actions/checkout@v2
       - uses: ./.github/actions/test
         with:
-          gleam-version: "0.34.1"
+          gleam-version: "1.0.0-rc1"
       - name: publish to hex
         env:
           HEXPM_USER: ${{ secrets.HEXPM_USER }}
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 143bc91..d2e3f69 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,9 @@
 
 ## [Unreleased](https://github.com/TanklesXL/glint/compare/v0.14.0...HEAD)
 
+## [0.15.0-rc1](https://github.com/TanklesXL/glint/compare/v0.14.0...v0.15.0-rc1)
+- support gleam >=0.34 or 1.0.x
+
 ## [0.15.0-rc1](https://github.com/TanklesXL/glint/compare/v0.14.0...v0.15.0-rc1)
 
 - refactor of help generation logic, no change to help text output
diff --git a/gleam.toml b/gleam.toml
index fd5d6f7..33e1ab6 100644
--- a/gleam.toml
+++ b/gleam.toml
@@ -11,7 +11,7 @@ links = [
     { title = "Hex", href = "https://hex.pm/packages/glint" },
     { title = "Docs", href = "https://hexdocs.pm/glint/" },
 ]
-gleam = ">= 0.33.0"
+gleam = ">=0.34.1 or ~> 1.0"
 
 [dependencies]
 gleam_stdlib = "~> 0.19"
diff --git a/src/glint.gleam b/src/glint.gleam
index a5c5f3e..9e1e780 100644
--- a/src/glint.gleam
+++ b/src/glint.gleam
@@ -652,8 +652,8 @@ fn build_subcommands_help(
     Metadata(
       name: name,
       description: cmd.contents
-      |> option.map(fn(command) { command.description })
-      |> option.unwrap(""),
+        |> option.map(fn(command) { command.description })
+        |> option.unwrap(""),
     ),
     ..acc
   ]
diff --git a/src/glint/flag/constraint.gleam b/src/glint/flag/constraint.gleam
index 91e370a..0130d7d 100644
--- a/src/glint/flag/constraint.gleam
+++ b/src/glint/flag/constraint.gleam
@@ -20,14 +20,14 @@ pub fn one_of(allowed: List(a)) -> Constraint(a) {
       False ->
         snag.error(
           "invalid value '"
-            <> string.inspect(val)
-            <> "', must be one of: ["
-            <> {
-              allowed
-              |> list.map(fn(a) { "'" <> string.inspect(a) <> "'" })
-              |> string.join(", ")
-            }
-            <> "]",
+          <> string.inspect(val)
+          <> "', must be one of: ["
+          <> {
+            allowed
+            |> list.map(fn(a) { "'" <> string.inspect(a) <> "'" })
+            |> string.join(", ")
+          }
+          <> "]",
         )
     }
   }
@@ -43,16 +43,16 @@ pub fn none_of(disallowed: List(a)) -> Constraint(a) {
       True ->
         snag.error(
           "invalid value '"
-            <> string.inspect(val)
-            <> "', must not be one of: ["
-            <> {
-              {
-                disallowed
-                |> list.map(fn(a) { "'" <> string.inspect(a) <> "'" })
-                |> string.join(", ")
-                <> "]"
-              }
-            },
+          <> string.inspect(val)
+          <> "', must not be one of: ["
+          <> {
+            {
+              disallowed
+              |> list.map(fn(a) { "'" <> string.inspect(a) <> "'" })
+              |> string.join(", ")
+              <> "]"
+            }
+          },
         )
     }
   }
diff --git a/test/glint/flag/contraint_test.gleam b/test/glint/flag/contraint_test.gleam
index 9de2493..bc57f13 100644
--- a/test/glint/flag/contraint_test.gleam
+++ b/test/glint/flag/contraint_test.gleam
@@ -60,78 +60,78 @@ pub fn flag_one_of_none_of_test() {
     #(
       "i",
       flag.int()
-      |> flag.constraint(one_of([1, 2, 3]))
-      |> flag.constraint(none_of([4, 5, 6]))
-      |> flag.build,
+        |> flag.constraint(one_of([1, 2, 3]))
+        |> flag.constraint(none_of([4, 5, 6]))
+        |> flag.build,
       "1",
       "6",
     ),
     #(
       "li",
       flag.int_list()
-      |> flag.constraint(
-        [1, 2, 3]
-        |> one_of
-        |> each,
-      )
-      |> flag.constraint(
-        [4, 5, 6]
-        |> none_of
-        |> each,
-      )
-      |> flag.build,
+        |> flag.constraint(
+          [1, 2, 3]
+          |> one_of
+          |> each,
+        )
+        |> flag.constraint(
+          [4, 5, 6]
+          |> none_of
+          |> each,
+        )
+        |> flag.build,
       "1,1,1",
       "2,2,6",
     ),
     #(
       "f",
       flag.float()
-      |> flag.constraint(one_of([1.0, 2.0, 3.0]))
-      |> flag.constraint(none_of([4.0, 5.0, 6.0]))
-      |> flag.build,
+        |> flag.constraint(one_of([1.0, 2.0, 3.0]))
+        |> flag.constraint(none_of([4.0, 5.0, 6.0]))
+        |> flag.build,
       "1.0",
       "6.0",
     ),
     #(
       "lf",
       flag.float_list()
-      |> flag.constraint(
-        [1.0, 2.0, 3.0]
-        |> one_of()
-        |> each,
-      )
-      |> flag.constraint(
-        [4.0, 5.0, 6.0]
-        |> none_of()
-        |> each,
-      )
-      |> flag.build,
+        |> flag.constraint(
+          [1.0, 2.0, 3.0]
+          |> one_of()
+          |> each,
+        )
+        |> flag.constraint(
+          [4.0, 5.0, 6.0]
+          |> none_of()
+          |> each,
+        )
+        |> flag.build,
       "3.0,2.0,1.0",
       "2.0,3.0,6.0",
     ),
     #(
       "s",
       flag.string()
-      |> flag.constraint(one_of(["t1", "t2", "t3"]))
-      |> flag.constraint(none_of(["t4", "t5", "t6"]))
-      |> flag.build,
+        |> flag.constraint(one_of(["t1", "t2", "t3"]))
+        |> flag.constraint(none_of(["t4", "t5", "t6"]))
+        |> flag.build,
       "t3",
       "t4",
     ),
     #(
       "ls",
       flag.string_list()
-      |> flag.constraint(
-        ["t1", "t2", "t3"]
-        |> one_of
-        |> each,
-      )
-      |> flag.constraint(
-        ["t4", "t5", "t6"]
-        |> none_of
-        |> each,
-      )
-      |> flag.build,
+        |> flag.constraint(
+          ["t1", "t2", "t3"]
+          |> one_of
+          |> each,
+        )
+        |> flag.constraint(
+          ["t4", "t5", "t6"]
+          |> none_of
+          |> each,
+        )
+        |> flag.build,
       "t3,t2,t1",
       "t2,t4,t1",
     ),
diff --git a/test/glint/flag_test.gleam b/test/glint/flag_test.gleam
index a077d48..5808b2b 100644
--- a/test/glint/flag_test.gleam
+++ b/test/glint/flag_test.gleam
@@ -99,20 +99,20 @@ pub fn flag_default_test() {
   let flag = #(
     "flag",
     flag.string()
-    |> flag.default("default"),
+      |> flag.default("default"),
   )
 
   glint.new()
   |> glint.add(
     ["cmd"],
     glint.command(fn(in: CommandInput) {
-      should.equal(in.args, args)
+        should.equal(in.args, args)
 
-      in.flags
-      |> map.get(flag.0)
-      |> should.equal(Ok(flag.build(flag.1)))
-    })
-    |> glint.flag_tuple(flag),
+        in.flags
+        |> map.get(flag.0)
+        |> should.equal(Ok(flag.build(flag.1)))
+      })
+      |> glint.flag_tuple(flag),
   )
   |> glint.execute(["cmd", ..args])
   |> should.be_ok()
@@ -134,7 +134,7 @@ pub fn flag_value_test() {
   |> glint.add(
     ["cmd"],
     glint.command(flag_value_should_be_set)
-    |> glint.flag_tuple(flag),
+      |> glint.flag_tuple(flag),
   )
   |> glint.execute(["cmd", flag_input, ..args])
   |> should.be_ok()
@@ -149,7 +149,7 @@ pub fn int_flag_test() {
   |> glint.add(
     [],
     glint.command(fn(_) { Nil })
-    |> glint.flag_tuple(flags),
+      |> glint.flag_tuple(flags),
   )
   |> glint.execute([flag_input])
   |> should.be_error()
@@ -166,7 +166,7 @@ pub fn int_flag_test() {
   |> glint.add(
     [],
     glint.command(expect_flag_value_of_10)
-    |> glint.flag_tuple(flags),
+      |> glint.flag_tuple(flags),
   )
   |> glint.execute([flag_input])
   |> should.be_ok()
@@ -181,7 +181,7 @@ pub fn bool_flag_test() {
   |> glint.add(
     [],
     glint.command(fn(_) { Nil })
-    |> glint.flag_tuple(flag),
+      |> glint.flag_tuple(flag),
   )
   |> glint.execute([flag_input])
   |> should.be_error()
@@ -197,7 +197,7 @@ pub fn bool_flag_test() {
   |> glint.add(
     [],
     glint.command(expect_flag_value_of_false)
-    |> glint.flag_tuple(flag),
+      |> glint.flag_tuple(flag),
   )
   |> glint.execute([flag_input])
   |> should.be_ok()
@@ -215,7 +215,7 @@ pub fn strings_flag_test() {
   |> glint.add(
     [],
     glint.command(expect_flag_value_list)
-    |> glint.flag_tuple(flags),
+      |> glint.flag_tuple(flags),
   )
   |> glint.execute([flag_input])
   |> should.be_ok()
@@ -230,7 +230,7 @@ pub fn ints_flag_test() {
   |> glint.add(
     [],
     glint.command(fn(_) { Nil })
-    |> glint.flag_tuple(flag),
+      |> glint.flag_tuple(flag),
   )
   |> glint.execute([flag_input])
   |> should.be_error()
@@ -246,7 +246,7 @@ pub fn ints_flag_test() {
   |> glint.add(
     [],
     glint.command(expect_flag_value_list)
-    |> glint.flag_tuple(flag),
+      |> glint.flag_tuple(flag),
   )
   |> glint.execute([flag_input])
   |> should.be_ok()
@@ -261,7 +261,7 @@ pub fn float_flag_test() {
   |> glint.add(
     [],
     glint.command(fn(_) { Nil })
-    |> glint.flag_tuple(flag),
+      |> glint.flag_tuple(flag),
   )
   |> glint.execute([flag_input])
   |> should.be_error()
@@ -278,7 +278,7 @@ pub fn float_flag_test() {
   |> glint.add(
     [],
     glint.command(expect_flag_value_of_10)
-    |> glint.flag_tuple(flag),
+      |> glint.flag_tuple(flag),
   )
   |> glint.execute([flag_input])
   |> should.be_ok()
@@ -293,7 +293,7 @@ pub fn floats_flag_test() {
   |> glint.add(
     [],
     glint.command(fn(_) { Nil })
-    |> glint.flag_tuple(flag),
+      |> glint.flag_tuple(flag),
   )
   |> glint.execute([flag_input])
   |> should.be_error()
@@ -309,7 +309,7 @@ pub fn floats_flag_test() {
   |> glint.add(
     [],
     glint.command(expect_flag_value_list)
-    |> glint.flag_tuple(flag),
+      |> glint.flag_tuple(flag),
   )
   |> glint.execute([flag_input])
   |> should.be_ok()
@@ -337,11 +337,11 @@ pub fn global_flag_test() {
   |> glint.add(
     at: [],
     do: glint.command(testcase([1.0, 2.0]))
-    |> glint.flag(
-      "flag",
-      flag.float_list()
-      |> flag.default([1.0, 2.0]),
-    ),
+      |> glint.flag(
+        "flag",
+        flag.float_list()
+          |> flag.default([1.0, 2.0]),
+      ),
   )
   |> glint.execute([])
   |> should.be_ok()
@@ -351,16 +351,16 @@ pub fn global_flag_test() {
   |> glint.global_flag(
     "flag",
     flag.float_list()
-    |> flag.default([3.0, 4.0]),
+      |> flag.default([3.0, 4.0]),
   )
   |> glint.add(
     at: [],
     do: glint.command(testcase([5.0, 6.0]))
-    |> glint.flag(
-      "flag",
-      flag.float_list()
-      |> flag.default([1.0, 2.0]),
-    ),
+      |> glint.flag(
+        "flag",
+        flag.float_list()
+          |> flag.default([1.0, 2.0]),
+      ),
   )
   |> glint.execute(["--flag=5.0,6.0"])
   |> should.be_ok()
@@ -373,7 +373,7 @@ pub fn toggle_test() {
   |> glint.add(
     [],
     glint.command(fn(_) { Nil })
-    |> glint.flag("flag", flag.bool()),
+      |> glint.flag("flag", flag.bool()),
   )
   |> glint.execute([flag_input])
   |> should.be_error()
@@ -385,11 +385,11 @@ pub fn toggle_test() {
   |> glint.add(
     [],
     glint.command(fn(in: CommandInput) {
-      in.flags
-      |> flag.get_bool(for: "flag")
-      |> should.equal(Ok(True))
-    })
-    |> glint.flag("flag", flag.bool()),
+        in.flags
+        |> flag.get_bool(for: "flag")
+        |> should.equal(Ok(True))
+      })
+      |> glint.flag("flag", flag.bool()),
   )
   |> glint.execute([flag_input])
   |> should.be_ok()
@@ -401,15 +401,15 @@ pub fn toggle_test() {
   |> glint.add(
     [],
     glint.command(fn(in: CommandInput) {
-      in.flags
-      |> flag.get_bool(for: "flag")
-      |> should.equal(Ok(False))
-    })
-    |> glint.flag(
-      "flag",
-      flag.bool()
-      |> flag.default(True),
-    ),
+        in.flags
+        |> flag.get_bool(for: "flag")
+        |> should.equal(Ok(False))
+      })
+      |> glint.flag(
+        "flag",
+        flag.bool()
+          |> flag.default(True),
+      ),
   )
   |> glint.execute([flag_input])
   |> should.be_ok()
@@ -419,11 +419,11 @@ pub fn toggle_test() {
   |> glint.add(
     [],
     glint.command(fn(in: CommandInput) {
-      in.flags
-      |> flag.get_bool(for: "flag")
-      |> should.equal(Ok(True))
-    })
-    |> glint.flag("flag", flag.bool()),
+        in.flags
+        |> flag.get_bool(for: "flag")
+        |> should.equal(Ok(True))
+      })
+      |> glint.flag("flag", flag.bool()),
   )
   |> glint.execute([flag_input])
   |> should.be_ok()
@@ -433,11 +433,11 @@ pub fn toggle_test() {
   |> glint.add(
     [],
     glint.command(fn(_) { Nil })
-    |> glint.flag(
-      "flag",
-      flag.int()
-      |> flag.default(1),
-    ),
+      |> glint.flag(
+        "flag",
+        flag.int()
+          |> flag.default(1),
+      ),
   )
   |> glint.execute([flag_input])
   |> should.be_error()
diff --git a/test/glint_test.gleam b/test/glint_test.gleam
index 08422cb..cda9c01 100644
--- a/test/glint_test.gleam
+++ b/test/glint_test.gleam
@@ -100,35 +100,35 @@ pub fn help_test() {
   let global_flag = #(
     "global",
     flag.string()
-    |> flag.description("This is a global flag"),
+      |> flag.description("This is a global flag"),
   )
 
   let flag_1 = #(
     "flag1",
     flag.string()
-    |> flag.description("This is flag1"),
+      |> flag.description("This is flag1"),
   )
 
   let flag_2 = #(
     "flag2",
     flag.int()
-    |> flag.description("This is flag2"),
+      |> flag.description("This is flag2"),
   )
   let flag_3 = #(
     "flag3",
     flag.bool()
-    |> flag.description("This is flag3"),
+      |> flag.description("This is flag3"),
   )
   let flag_4 = #(
     "flag4",
     flag.float()
-    |> flag.description("This is flag4"),
+      |> flag.description("This is flag4"),
   )
 
   let flag_5 = #(
     "flag5",
     flag.float_list()
-    |> flag.description("This is flag5"),
+      |> flag.description("This is flag5"),
   )
 
   let cli =
@@ -139,40 +139,40 @@ pub fn help_test() {
     |> glint.add(
       at: [],
       do: glint.command(do: nil)
-      |> glint.named_args(["arg1", "arg2"])
-      |> glint.flag(flag_1.0, flag_1.1)
-      |> glint.description("This is the root command"),
+        |> glint.named_args(["arg1", "arg2"])
+        |> glint.flag(flag_1.0, flag_1.1)
+        |> glint.description("This is the root command"),
     )
     |> glint.add(
       at: ["cmd1"],
       do: glint.command(nil)
-      |> glint.flag(flag_2.0, flag_2.1)
-      |> glint.flag(flag_5.0, flag_5.1)
-      |> glint.description("This is cmd1"),
+        |> glint.flag(flag_2.0, flag_2.1)
+        |> glint.flag(flag_5.0, flag_5.1)
+        |> glint.description("This is cmd1"),
     )
     |> glint.add(
       at: ["cmd1", "cmd3"],
       do: glint.command(nil)
-      |> glint.flag(flag_3.0, flag_3.1)
-      |> glint.description("This is cmd3"),
+        |> glint.flag(flag_3.0, flag_3.1)
+        |> glint.description("This is cmd3"),
     )
     |> glint.add(
       at: ["cmd1", "cmd4"],
       do: glint.command(nil)
-      |> glint.flag(flag_4.0, flag_4.1)
-      |> glint.description("This is cmd4"),
+        |> glint.flag(flag_4.0, flag_4.1)
+        |> glint.description("This is cmd4"),
     )
     |> glint.add(
       at: ["cmd2"],
       do: glint.command(nil)
-      |> glint.named_args(["arg1", "arg2"])
-      |> glint.count_args(glint.MinArgs(2))
-      |> glint.description("This is cmd2"),
+        |> glint.named_args(["arg1", "arg2"])
+        |> glint.count_args(glint.MinArgs(2))
+        |> glint.description("This is cmd2"),
     )
     |> glint.add(
       at: ["cmd5", "cmd6"],
       do: glint.command(nil)
-      |> glint.description("This is cmd6"),
+        |> glint.description("This is cmd6"),
     )
 
   // execute root command
@@ -266,8 +266,8 @@ pub fn global_flags_test() {
     |> glint.global_flag(
       "f",
       flag.int()
-      |> flag.default(2)
-      |> flag.description("global flag example"),
+        |> flag.default(2)
+        |> flag.description("global flag example"),
     )
     |> glint.add(
       [],
@@ -279,15 +279,15 @@ pub fn global_flags_test() {
     |> glint.add(
       ["sub"],
       glint.command(fn(ctx) {
-        flag.get_bool(ctx.flags, "f")
-        |> should.equal(Ok(True))
-      })
-      |> glint.flag(
-        "f",
-        flag.bool()
-        |> flag.default(True)
-        |> flag.description("i decided to override the global flag"),
-      ),
+          flag.get_bool(ctx.flags, "f")
+          |> should.equal(Ok(True))
+        })
+        |> glint.flag(
+          "f",
+          flag.bool()
+            |> flag.default(True)
+            |> flag.description("i decided to override the global flag"),
+        ),
     )
 
   // root command keeps the global flag as an int