diff --git a/.github/FUNDING.yml b/.github/FUNDING.yml
new file mode 100644
index 0000000..fc5ebc9
--- /dev/null
+++ b/.github/FUNDING.yml
@@ -0,0 +1 @@
+github: muesli
diff --git a/.github/dependabot.yml b/.github/dependabot.yml
new file mode 100644
index 0000000..a8f1d82
--- /dev/null
+++ b/.github/dependabot.yml
@@ -0,0 +1,14 @@
+version: 2
+updates:
+  - package-ecosystem: "gomod"
+    directory: "/"
+    schedule:
+      interval: "daily"
+    labels:
+      - "dependencies"
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "daily"
+    labels:
+      - "dependencies"
diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
new file mode 100644
index 0000000..b0e2ea0
--- /dev/null
+++ b/.github/workflows/build.yml
@@ -0,0 +1,29 @@
+name: build
+on: [push, pull_request]
+
+jobs:
+  build:
+    strategy:
+      matrix:
+        go-version: [~1.11, ^1]
+        os: [ubuntu-latest, macos-latest, windows-latest]
+    runs-on: ${{ matrix.os }}
+    env:
+      GO111MODULE: "on"
+    steps:
+      - name: Install Go
+        uses: actions/setup-go@v2
+        with:
+          go-version: ${{ matrix.go-version }}
+
+      - name: Checkout code
+        uses: actions/checkout@v3
+
+      - name: Download Go modules
+        run: go mod download
+
+      - name: Build
+        run: go build -v ./...
+
+      - name: Test
+        run: go test ./...
diff --git a/.github/workflows/coverage.yml b/.github/workflows/coverage.yml
new file mode 100644
index 0000000..09c963b
--- /dev/null
+++ b/.github/workflows/coverage.yml
@@ -0,0 +1,28 @@
+name: coverage
+on: [push, pull_request]
+
+jobs:
+  coverage:
+    strategy:
+      matrix:
+        go-version: [^1]
+        os: [ubuntu-latest]
+    runs-on: ${{ matrix.os }}
+    env:
+      GO111MODULE: "on"
+    steps:
+      - name: Install Go
+        uses: actions/setup-go@v2
+        with:
+          go-version: ${{ matrix.go-version }}
+
+      - name: Checkout code
+        uses: actions/checkout@v3
+
+      - name: Coverage
+        env:
+          COVERALLS_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          go test -race -covermode atomic -coverprofile=profile.cov ./...
+          GO111MODULE=off go get github.com/mattn/goveralls
+          $(go env GOPATH)/bin/goveralls -coverprofile=profile.cov -service=github
diff --git a/.github/workflows/lint-soft.yml b/.github/workflows/lint-soft.yml
new file mode 100644
index 0000000..d5fd7f9
--- /dev/null
+++ b/.github/workflows/lint-soft.yml
@@ -0,0 +1,23 @@
+name: lint-soft
+on:
+  push:
+  pull_request:
+
+permissions:
+  contents: read
+  # Optional: allow read access to pull request. Use with `only-new-issues` option.
+  pull-requests: read
+
+jobs:
+  golangci:
+    name: lint-soft
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - name: golangci-lint
+        uses: golangci/golangci-lint-action@v3
+        with:
+          # Optional: golangci-lint command line arguments.
+          args: --config .golangci-soft.yml --issues-exit-code=0
+          # Optional: show only new issues if it's a pull request. The default value is `false`.
+          only-new-issues: true
diff --git a/.github/workflows/lint.yml b/.github/workflows/lint.yml
new file mode 100644
index 0000000..8851983
--- /dev/null
+++ b/.github/workflows/lint.yml
@@ -0,0 +1,23 @@
+name: lint
+on:
+  push:
+  pull_request:
+
+permissions:
+  contents: read
+  # Optional: allow read access to pull request. Use with `only-new-issues` option.
+  pull-requests: read
+
+jobs:
+  golangci:
+    name: lint
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - name: golangci-lint
+        uses: golangci/golangci-lint-action@v3
+        with:
+          # Optional: golangci-lint command line arguments.
+          #args:
+          # Optional: show only new issues if it's a pull request. The default value is `false`.
+          only-new-issues: true
diff --git a/.golangci-soft.yml b/.golangci-soft.yml
new file mode 100644
index 0000000..ef456e0
--- /dev/null
+++ b/.golangci-soft.yml
@@ -0,0 +1,47 @@
+run:
+  tests: false
+
+issues:
+  include:
+    - EXC0001
+    - EXC0005
+    - EXC0011
+    - EXC0012
+    - EXC0013
+
+  max-issues-per-linter: 0
+  max-same-issues: 0
+
+linters:
+  enable:
+    # - dupl
+    - exhaustive
+    # - exhaustivestruct
+    - goconst
+    - godot
+    - godox
+    - gomnd
+    - gomoddirectives
+    - goprintffuncname
+    - ifshort
+    # - lll
+    - misspell
+    - nakedret
+    - nestif
+    - noctx
+    - nolintlint
+    - prealloc
+    - wrapcheck
+
+  # disable default linters, they are already enabled in .golangci.yml
+  disable:
+    - deadcode
+    - errcheck
+    - gosimple
+    - govet
+    - ineffassign
+    - staticcheck
+    - structcheck
+    - typecheck
+    - unused
+    - varcheck
diff --git a/.golangci.yml b/.golangci.yml
new file mode 100644
index 0000000..a5a91d0
--- /dev/null
+++ b/.golangci.yml
@@ -0,0 +1,29 @@
+run:
+  tests: false
+
+issues:
+  include:
+    - EXC0001
+    - EXC0005
+    - EXC0011
+    - EXC0012
+    - EXC0013
+
+  max-issues-per-linter: 0
+  max-same-issues: 0
+
+linters:
+  enable:
+    - bodyclose
+    - exportloopref
+    - goimports
+    - gosec
+    - nilerr
+    - predeclared
+    - revive
+    - rowserrcheck
+    - sqlclosecheck
+    - tparallel
+    - unconvert
+    - unparam
+    - whitespace
diff --git a/.travis.yml b/.travis.yml
deleted file mode 100644
index ae2d044..0000000
--- a/.travis.yml
+++ /dev/null
@@ -1,38 +0,0 @@
-language: go
-
-os:
-  - linux
-  - osx
-
-go:
-  - 1.5.x
-  - 1.6.x
-  - 1.7.x
-  - 1.8.x
-  - 1.9.x
-  - 1.10.x
-  - 1.11.x
-  - 1.12.x
-  - tip
-
-matrix:
-  allow_failures:
-    - go: tip
-
-  exclude:
-    - os: osx
-      go: 1.5.x
-    - os: osx
-      go: 1.6.x
-
-before_install:
-  - if [[ $TRAVIS_GO_VERSION == 1.12* ]]; then go get github.com/axw/gocov/gocov github.com/mattn/goveralls; fi
-
-script:
-  - go test -v -tags ci ./...
-  - if [[ $TRAVIS_GO_VERSION == 1.12* ]]; then $GOPATH/bin/goveralls -service=travis-ci -ignore="examples/tokens/tokens.go,examples/space/space.go"; fi
-
-notifications:
-  email:
-    on_success: change
-    on_failure: always
diff --git a/LICENSE b/LICENSE
index dbbe355..6a766f8 100644
--- a/LICENSE
+++ b/LICENSE
@@ -1,661 +1,21 @@
-                    GNU AFFERO GENERAL PUBLIC LICENSE
-                       Version 3, 19 November 2007
-
- Copyright (C) 2007 Free Software Foundation, Inc. <http://fsf.org/>
- Everyone is permitted to copy and distribute verbatim copies
- of this license document, but changing it is not allowed.
-
-                            Preamble
-
-  The GNU Affero General Public License is a free, copyleft license for
-software and other kinds of works, specifically designed to ensure
-cooperation with the community in the case of network server software.
-
-  The licenses for most software and other practical works are designed
-to take away your freedom to share and change the works.  By contrast,
-our General Public Licenses are intended to guarantee your freedom to
-share and change all versions of a program--to make sure it remains free
-software for all its users.
-
-  When we speak of free software, we are referring to freedom, not
-price.  Our General Public Licenses are designed to make sure that you
-have the freedom to distribute copies of free software (and charge for
-them if you wish), that you receive source code or can get it if you
-want it, that you can change the software or use pieces of it in new
-free programs, and that you know you can do these things.
-
-  Developers that use our General Public Licenses protect your rights
-with two steps: (1) assert copyright on the software, and (2) offer
-you this License which gives you legal permission to copy, distribute
-and/or modify the software.
-
-  A secondary benefit of defending all users' freedom is that
-improvements made in alternate versions of the program, if they
-receive widespread use, become available for other developers to
-incorporate.  Many developers of free software are heartened and
-encouraged by the resulting cooperation.  However, in the case of
-software used on network servers, this result may fail to come about.
-The GNU General Public License permits making a modified version and
-letting the public access it on a server without ever releasing its
-source code to the public.
-
-  The GNU Affero General Public License is designed specifically to
-ensure that, in such cases, the modified source code becomes available
-to the community.  It requires the operator of a network server to
-provide the source code of the modified version running there to the
-users of that server.  Therefore, public use of a modified version, on
-a publicly accessible server, gives the public access to the source
-code of the modified version.
-
-  An older license, called the Affero General Public License and
-published by Affero, was designed to accomplish similar goals.  This is
-a different license, not a version of the Affero GPL, but Affero has
-released a new version of the Affero GPL which permits relicensing under
-this license.
-
-  The precise terms and conditions for copying, distribution and
-modification follow.
-
-                       TERMS AND CONDITIONS
-
-  0. Definitions.
-
-  "This License" refers to version 3 of the GNU Affero General Public License.
-
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-works, such as semiconductor masks.
-
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-"recipients" may be individuals or organizations.
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-extent that warranties are provided), that licensees may convey the
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-possible use to the public, the best way to achieve this is to make it
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-    Copyright (C) <year>  <name of author>
-
-    This program is free software: you can redistribute it and/or modify
-    it under the terms of the GNU Affero General Public License as published
-    by the Free Software Foundation, either version 3 of the License, or
-    (at your option) any later version.
-
-    This program is distributed in the hope that it will be useful,
-    but WITHOUT ANY WARRANTY; without even the implied warranty of
-    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-    GNU Affero General Public License for more details.
-
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-    along with this program.  If not, see <http://www.gnu.org/licenses/>.
-
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-if any, to sign a "copyright disclaimer" for the program, if necessary.
-For more information on this, and how to apply and follow the GNU AGPL, see
-<http://www.gnu.org/licenses/>.
+MIT License
+
+Copyright (c) 2022 Christian Muehlhaeuser
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/README.md b/README.md
index 7f6b989..e944b69 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,7 @@
 toktok
 ======
 
+[![Latest Release](https://img.shields.io/github/release/muesli/toktok.svg)](https://github.com/muesli/toktok/releases)
 [![Build Status](https://travis-ci.org/muesli/toktok.svg?branch=master)](https://travis-ci.org/muesli/toktok)
 [![Coverage Status](https://coveralls.io/repos/github/muesli/toktok/badge.svg?branch=master)](https://coveralls.io/github/muesli/toktok?branch=master)
 [![Go ReportCard](https://goreportcard.com/badge/muesli/toktok)](https://goreportcard.com/report/muesli/toktok)
@@ -14,17 +15,17 @@ guarantees a safety distance between the tokens, so they become resilient to typ
 
 ## Installation
 
-Make sure you have a working Go environment (Go 1.5 or higher is required).
+Make sure you have a working Go environment (Go 1.11 or higher is required).
 See the [install instructions](https://golang.org/doc/install.html).
 
 To install toktok, simply run:
 
     go get github.com/muesli/toktok
 
-To compile it from source:
+Compiling toktok is easy, simply run:
 
-    cd $GOPATH/src/github.com/muesli/toktok
-    go get -u -v
+    git clone https://github.com/muesli/toktok.git
+    cd toktok
     go build && go test -v
 
 ## Example
@@ -38,22 +39,24 @@ import (
 )
 
 func main() {
-	// Generate a new token bucket. Each generated token will be 8 characters long
+	// Generate a new token bucket.
+	// Each generated token will be 8 characters long.
 	bucket, _ := toktok.NewBucket(8)
 
-	// Generate a bunch of tokens with a safety distance of 4
-	// Distance is calculated by insertion cost (1), deletion cost (1) and substitution cost (2)
+	// Generate a bunch of tokens with a safety distance of 4.
+	// Distance is calculated by insertion cost (1), deletion cost (1) and
+	// substitution cost (2).
 	for i := 0; i < 9; i++ {
 		token, _ := bucket.NewToken(4)
 		fmt.Printf("Generated Token %d: %s\n", i, token)
 	}
 
-	// One more token that we will tamper with
+	// One more token that we will tamper with.
 	token, _ := bucket.NewToken(4)
 	fmt.Printf("Generated Token 9: %s\n", token)
 	token = "_" + token[1:7] + "_"
 
-	// Find the closest match for the faulty token
+	// Find the closest match for the faulty token.
 	match, distance := bucket.Resolve(token)
 	fmt.Printf("Best match for '%s' is token '%s' with distance %d\n", token, match, distance)
 }
@@ -68,3 +71,10 @@ Generated Token 2: WNANK4FU
 Generated Token 9: Y3NCDFWN
 Best match for '_3NCDFW_' is token 'Y3NCDFWN' with distance 4
 ```
+
+## Feedback
+
+Got some feedback or suggestions? Please open an issue or drop me a note!
+
+* [Twitter](https://twitter.com/mueslix)
+* [The Fediverse](https://mastodon.social/@fribbledom)
diff --git a/debian/changelog b/debian/changelog
index 4b73b3e..115b5c0 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,3 +1,9 @@
+golang-github-muesli-toktok (0.0~git20220302.179402c-1) UNRELEASED; urgency=low
+
+  * New upstream snapshot.
+
+ -- Debian Janitor <janitor@jelmer.uk>  Wed, 16 Mar 2022 23:17:08 -0000
+
 golang-github-muesli-toktok (0.0~git20210519.2b0817e-2) unstable; urgency=medium
 
   * Source-only upload for migration to testing
diff --git a/errors.go b/errors.go
index af99165..0e98524 100644
--- a/errors.go
+++ b/errors.go
@@ -1,6 +1,6 @@
 /*
  * Human-friendly token generator
- *     Copyright (c) 2017, Christian Muehlhaeuser <muesli@gmail.com>
+ *     Copyright (c) 2017-2022, Christian Muehlhaeuser <muesli@gmail.com>
  *
  *   For license see LICENSE
  */
diff --git a/examples/tokens/tokens.go b/examples/tokens/tokens.go
index 7d2b7e0..8760e45 100644
--- a/examples/tokens/tokens.go
+++ b/examples/tokens/tokens.go
@@ -7,22 +7,24 @@ import (
 )
 
 func main() {
-	// Generate a new token bucket. Each generated token will be 8 characters long
+	// Generate a new token bucket.
+	// Each generated token will be 8 characters long.
 	bucket, _ := toktok.NewBucket(8)
 
-	// Generate a bunch of tokens with a safety distance of 4
-	// Distance is calculated by insertion cost (1), deletion cost (1) and substitution cost (2)
+	// Generate a bunch of tokens with a safety distance of 4.
+	// Distance is calculated by insertion cost (1), deletion cost (1) and
+	// substitution cost (2).
 	for i := 0; i < 9; i++ {
 		token, _ := bucket.NewToken(4)
 		fmt.Printf("Generated Token %d: %s\n", i, token)
 	}
 
-	// One more token that we will tamper with
+	// One more token that we will tamper with.
 	token, _ := bucket.NewToken(4)
 	fmt.Printf("Generated Token 9: %s\n", token)
 	token = "_" + token[1:7] + "_"
 
-	// Find the closest match for the faulty token
+	// Find the closest match for the faulty token.
 	match, distance := bucket.Resolve(token)
 	fmt.Printf("Best match for '%s' is token '%s' with distance %d\n", token, match, distance)
 }
diff --git a/go.mod b/go.mod
index 0209fe5..0310aa0 100644
--- a/go.mod
+++ b/go.mod
@@ -2,4 +2,4 @@ module github.com/muesli/toktok
 
 go 1.15
 
-require github.com/xrash/smetrics v0.0.0-20200730060457-89a2a8a1fb0b
+require github.com/xrash/smetrics v0.0.0-20201216005158-039620a65673
diff --git a/go.sum b/go.sum
index c3d6f32..2b1a9ab 100644
--- a/go.sum
+++ b/go.sum
@@ -1,2 +1,2 @@
-github.com/xrash/smetrics v0.0.0-20200730060457-89a2a8a1fb0b h1:tnWgqoOBmInkt5pbLjagwNVjjT4RdJhFHzL1ebCSRh8=
-github.com/xrash/smetrics v0.0.0-20200730060457-89a2a8a1fb0b/go.mod h1:N3UwUGtsrSj3ccvlPHLoLsHnpR27oXr4ZE984MbSER8=
+github.com/xrash/smetrics v0.0.0-20201216005158-039620a65673 h1:bAn7/zixMGCfxrRTfdpNzjtPYqr8smhKouy9mxVdGPU=
+github.com/xrash/smetrics v0.0.0-20201216005158-039620a65673/go.mod h1:N3UwUGtsrSj3ccvlPHLoLsHnpR27oXr4ZE984MbSER8=
diff --git a/toktok.go b/toktok.go
index 641d119..9758b69 100644
--- a/toktok.go
+++ b/toktok.go
@@ -1,6 +1,6 @@
 /*
  * Human-friendly token generator
- *     Copyright (c) 2017, Christian Muehlhaeuser <muesli@gmail.com>
+ *     Copyright (c) 2017-2022, Christian Muehlhaeuser <muesli@gmail.com>
  *
  *   For license see LICENSE
  */
@@ -16,7 +16,7 @@ import (
 	"github.com/xrash/smetrics"
 )
 
-// Bucket tracks all the generated tokens and lets you create new, unique tokens
+// Bucket tracks all the generated tokens and lets you create new, unique tokens.
 type Bucket struct {
 	length uint
 	runes  []rune
@@ -27,12 +27,23 @@ type Bucket struct {
 	sync.RWMutex
 }
 
-// NewBucket returns a new bucket, which will contain tokens of tokenLength
+// NewBucket returns a new bucket, which will contain tokens of tokenLength.
 func NewBucket(tokenLength uint) (Bucket, error) {
-	return NewBucketWithRunes(tokenLength, "ACDEFHJKLMNPRSTUWXY3469")
+	// Problematic chars:
+	//  - A and 4
+	//  - B and 8
+	//  - G and 6
+	//  - I and 1
+	//  - O and Q, 0
+	//  - Q and O, 0
+	//  - S and 5
+	//  - U and V
+	//	- Z and 2, 7
+	return NewBucketWithRunes(tokenLength, "ABCDEFHJKLMNPRSTUWXY369")
 }
 
-// NewBucketWithRunes returns a new bucket and let's you define which runes will be used for token generation
+// NewBucketWithRunes returns a new bucket and lets you define which runes will
+// be used for token generation.
 func NewBucketWithRunes(tokenLength uint, runes string) (Bucket, error) {
 	runes = strings.ToUpper(runes)
 	for _, r := range runes {
@@ -55,7 +66,7 @@ func NewBucketWithRunes(tokenLength uint, runes string) (Bucket, error) {
 	}, nil
 }
 
-// LoadTokens adds previously generated tokens to the Bucket
+// LoadTokens adds previously generated tokens to the Bucket.
 func (bucket *Bucket) LoadTokens(tokens []string) {
 	bucket.Lock()
 	defer bucket.Unlock()
@@ -65,7 +76,8 @@ func (bucket *Bucket) LoadTokens(tokens []string) {
 	}
 }
 
-// NewToken returns a new token with a minimal safety distance to all other existing tokens
+// NewToken returns a new token with a minimal safety distance to all other
+// existing tokens.
 func (bucket *Bucket) NewToken(distance int) (string, error) {
 	if distance < 1 {
 		return "", ErrDistanceTooSmall
@@ -89,7 +101,8 @@ func (bucket *Bucket) NewToken(distance int) (string, error) {
 	return c, nil
 }
 
-// Resolve tries to find the matching original token for a potentially corrupted token
+// Resolve tries to find the matching original token for a potentially corrupted
+// token.
 func (bucket *Bucket) Resolve(code string) (string, int) {
 	distance := 65536
 
@@ -120,7 +133,7 @@ func (bucket *Bucket) Resolve(code string) (string, int) {
 	return t, distance
 }
 
-// Count returns how many tokens are currently in this Bucket
+// Count returns how many tokens are currently in this Bucket.
 func (bucket *Bucket) Count() uint64 {
 	bucket.Lock()
 	defer bucket.Unlock()
@@ -128,7 +141,7 @@ func (bucket *Bucket) Count() uint64 {
 	return uint64(len(bucket.tokens))
 }
 
-// EstimatedFillPercentage returns how full the Bucket approximately is
+// EstimatedFillPercentage returns how full the Bucket approximately is.
 func (bucket *Bucket) EstimatedFillPercentage() float64 {
 	bucket.Lock()
 	defer bucket.Unlock()
@@ -145,7 +158,8 @@ func (bucket *Bucket) EstimatedFillPercentage() float64 {
 	return 100.0 - (100.0 / (float64(tries) / float64(len(bucket.tries))))
 }
 
-// EstimatedTokenSpace returns the total estimated token space available in this Bucket
+// EstimatedTokenSpace returns the total estimated token space available in this
+// Bucket.
 func (bucket *Bucket) EstimatedTokenSpace() uint64 {
 	return uint64(float64(bucket.Count()) * (100.0 / bucket.EstimatedFillPercentage()))
 }
@@ -179,7 +193,8 @@ func (bucket *Bucket) generate(distance int) (string, int, error) {
 	return c, i, nil
 }
 
-// GenerateToken generates a new token of length n with the defined rune-set letterRunes
+// GenerateToken generates a new token of length n with the defined rune-set
+// letterRunes.
 func GenerateToken(n uint, letterRunes []rune) string {
 	l := len(letterRunes)
 	b := make([]rune, n)
@@ -191,7 +206,7 @@ func GenerateToken(n uint, letterRunes []rune) string {
 		}
 		b[i] = lastrune
 		for lastrune == b[i] {
-			b[i] = letterRunes[rand.Intn(l)]
+			b[i] = letterRunes[rand.Intn(l)] //nolint:gosec
 		}
 	}
 
diff --git a/toktok_test.go b/toktok_test.go
index 9bac370..96c90c2 100644
--- a/toktok_test.go
+++ b/toktok_test.go
@@ -1,6 +1,6 @@
 /*
  * Human-friendly token generator
- *     Copyright (c) 2017, Christian Muehlhaeuser <muesli@gmail.com>
+ *     Copyright (c) 2017-2022, Christian Muehlhaeuser <muesli@gmail.com>
  *
  *   For license see LICENSE
  */