diff --git a/.mill-version b/.mill-version
new file mode 100644
index 0000000..83f6fe1
--- /dev/null
+++ b/.mill-version
@@ -0,0 +1 @@
+0.12.14-native
diff --git a/build.mill b/build.mill
new file mode 100644
index 0000000..6c97279
--- /dev/null
+++ b/build.mill
@@ -0,0 +1,53 @@
+package build
+
+import mill._, javalib._, errorprone._
+
+object `package` extends RootModule with JavaModule with ErrorProneModule {
+
+  def artifactName = "vavr-effect"
+
+  def javacOptions = super.javacOptions() ++ Seq(
+    "-Xlint:unchecked",
+    "-Xlint:rawtypes")
+
+  def errorProneVersion = "2.28.0"
+
+  def errorProneOptions = Seq(
+    "-Xep:NullAway:ERROR",
+    "-XepOpt:NullAway:AnnotatedPackages=com.github.tonivade.vavr.effect",
+    "-XepOpt:NullAway:SuggestSuppressions=true",
+    "-XDcompilePolicy=simple",
+    "-XDshould-stop.ifError=FLOW",
+    "-XDshouldStopPolicyIfError=FLOW"
+  )
+  
+  def errorProneDeps = super.errorProneDeps() ++
+    Agg(ivy"com.uber.nullaway:nullaway:0.12.7")
+
+  def ivyDeps = super.ivyDeps() ++ Agg(ivy"io.vavr:vavr:0.10.6")
+  
+  def sources = Task.Sources {
+    Seq(PathRef(millSourcePath / "src" / "main" / "java"))
+  }
+
+  def compileIvyDeps = super.compileIvyDeps() ++
+    Agg(ivy"org.jspecify:jspecify:1.0.0")
+
+  def publishVersion = "0.1-SNAPSHOT"
+
+  object test extends JavaTests with TestModule.Junit5 {
+
+    def ivyDeps = super.ivyDeps() ++ Agg(
+      ivy"org.junit.jupiter:junit-jupiter:5.12.2",
+      ivy"org.mockito:mockito-core:5.18.0",
+      ivy"org.mockito:mockito-junit-jupiter:5.18.0"
+    )
+
+    def sources = Task.Sources {
+      Seq(PathRef(millSourcePath / "src" / "test" / "java"))
+    }
+
+    def testSandboxWorkingDir = false
+    def testEnableWorkStealing = false
+  }
+}
diff --git a/mill b/mill
new file mode 100755
index 0000000..555d7fc
--- /dev/null
+++ b/mill
@@ -0,0 +1,327 @@
+#!/usr/bin/env sh
+
+# This is a wrapper script, that automatically selects or downloads Mill from Maven Central or GitHub release pages.
+#
+# This script determines the Mill version to use by trying these sources
+#   - env-variable `MILL_VERSION`
+#   - local file `.mill-version`
+#   - local file `.config/mill-version`
+#   - `mill-version` from YAML fronmatter of current buildfile
+#   - if accessible, find the latest stable version available on Maven Central (https://repo1.maven.org/maven2)
+#   - env-variable `DEFAULT_MILL_VERSION`
+#
+# If a version has the suffix '-native' a native binary will be used.
+# If a version has the suffix '-jvm' an executable jar file will be used, requiring an already installed Java runtime.
+# If no such suffix is found, the script will pick a default based on version and platform.
+#
+# Once a version was determined, it tries to use either
+#    - a system-installed mill, if found and it's version matches
+#    - an already downloaded version under ~/.cache/mill/download
+#
+# If no working mill version was found on the system,
+# this script downloads a binary file from Maven Central or Github Pages (this is version dependent)
+# into a cache location (~/.cache/mill/download).
+#
+# Mill Project URL: https://github.com/com-lihaoyi/mill
+# Script Version: 1.0.0-M1-49-ac90e3
+#
+# If you want to improve this script, please also contribute your changes back!
+# This script was generated from: dist/scripts/src/mill.sh
+#
+# Licensed under the Apache License, Version 2.0
+
+set -e
+
+if [ -z "${DEFAULT_MILL_VERSION}" ] ; then
+  DEFAULT_MILL_VERSION=0.12.14
+fi
+
+
+if [ -z "${GITHUB_RELEASE_CDN}" ] ; then
+  GITHUB_RELEASE_CDN=""
+fi
+
+
+MILL_REPO_URL="https://github.com/com-lihaoyi/mill"
+
+if [ -z "${CURL_CMD}" ] ; then
+  CURL_CMD=curl
+fi
+
+# Explicit commandline argument takes precedence over all other methods
+if [ "$1" = "--mill-version" ] ; then
+    echo "The --mill-version option is no longer supported." 1>&2
+fi
+
+MILL_BUILD_SCRIPT=""
+
+if [ -f "build.mill" ] ; then
+  MILL_BUILD_SCRIPT="build.mill"
+elif [ -f "build.mill.scala" ] ; then
+  MILL_BUILD_SCRIPT="build.mill.scala"
+elif [ -f "build.sc" ] ; then
+  MILL_BUILD_SCRIPT="build.sc"
+fi
+
+# Please note, that if a MILL_VERSION is already set in the environment,
+# We reuse it's value and skip searching for a value.
+
+# If not already set, read .mill-version file
+if [ -z "${MILL_VERSION}" ] ; then
+  if [ -f ".mill-version" ] ; then
+    MILL_VERSION="$(tr '\r' '\n' < .mill-version | head -n 1 2> /dev/null)"
+  elif [ -f ".config/mill-version" ] ; then
+    MILL_VERSION="$(tr '\r' '\n' < .config/mill-version | head -n 1 2> /dev/null)"
+  elif [ -n "${MILL_BUILD_SCRIPT}" ] ; then
+    MILL_VERSION="$(cat ${MILL_BUILD_SCRIPT} | grep '//[|]  *mill-version:  *' | sed 's;//|  *mill-version:  *;;')"
+  fi
+fi
+
+MILL_USER_CACHE_DIR="${XDG_CACHE_HOME:-${HOME}/.cache}/mill"
+
+if [ -z "${MILL_DOWNLOAD_PATH}" ] ; then
+  MILL_DOWNLOAD_PATH="${MILL_USER_CACHE_DIR}/download"
+fi
+
+# If not already set, try to fetch newest from Github
+if [ -z "${MILL_VERSION}" ] ; then
+  # TODO: try to load latest version from release page
+  echo "No mill version specified." 1>&2
+  echo "You should provide a version via a '//| mill-version: ' comment or a '.mill-version' file." 1>&2
+
+  mkdir -p "${MILL_DOWNLOAD_PATH}"
+  LANG=C touch -d '1 hour ago' "${MILL_DOWNLOAD_PATH}/.expire_latest" 2>/dev/null || (
+    # we might be on OSX or BSD which don't have -d option for touch
+    # but probably a -A [-][[hh]mm]SS
+    touch "${MILL_DOWNLOAD_PATH}/.expire_latest"; touch -A -010000 "${MILL_DOWNLOAD_PATH}/.expire_latest"
+  ) || (
+    # in case we still failed, we retry the first touch command with the intention
+    # to show the (previously suppressed) error message
+    LANG=C touch -d '1 hour ago' "${MILL_DOWNLOAD_PATH}/.expire_latest"
+  )
+
+  # POSIX shell variant of bash's -nt operator, see https://unix.stackexchange.com/a/449744/6993
+  # if [ "${MILL_DOWNLOAD_PATH}/.latest" -nt "${MILL_DOWNLOAD_PATH}/.expire_latest" ] ; then
+  if [ -n "$(find -L "${MILL_DOWNLOAD_PATH}/.latest" -prune -newer "${MILL_DOWNLOAD_PATH}/.expire_latest")" ]; then
+    # we know a current latest version
+    MILL_VERSION=$(head -n 1 "${MILL_DOWNLOAD_PATH}"/.latest 2> /dev/null)
+  fi
+
+  if [ -z "${MILL_VERSION}" ] ; then
+    # we don't know a current latest version
+    echo "Retrieving latest mill version ..." 1>&2
+    LANG=C ${CURL_CMD} -s -i -f -I ${MILL_REPO_URL}/releases/latest 2> /dev/null  | grep --ignore-case Location: | sed s'/^.*tag\///' | tr -d '\r\n' > "${MILL_DOWNLOAD_PATH}/.latest"
+    MILL_VERSION=$(head -n 1 "${MILL_DOWNLOAD_PATH}"/.latest 2> /dev/null)
+  fi
+
+  if [ -z "${MILL_VERSION}" ] ; then
+    # Last resort
+    MILL_VERSION="${DEFAULT_MILL_VERSION}"
+    echo "Falling back to hardcoded mill version ${MILL_VERSION}" 1>&2
+  else
+    echo "Using mill version ${MILL_VERSION}" 1>&2
+  fi
+fi
+
+MILL_NATIVE_SUFFIX="-native"
+MILL_JVM_SUFFIX="-jvm"
+FULL_MILL_VERSION=$MILL_VERSION
+ARTIFACT_SUFFIX=""
+set_artifact_suffix(){
+  if [ "$(expr substr $(uname -s) 1 5 2>/dev/null)" = "Linux" ]; then
+    if [ "$(uname -m)" = "aarch64" ]; then
+      ARTIFACT_SUFFIX="-native-linux-aarch64"
+    else
+      ARTIFACT_SUFFIX="-native-linux-amd64"
+    fi
+  elif [ "$(uname)" = "Darwin" ]; then
+    if [ "$(uname -m)" = "arm64" ]; then
+      ARTIFACT_SUFFIX="-native-mac-aarch64"
+    else
+      ARTIFACT_SUFFIX="-native-mac-amd64"
+    fi
+  else
+     echo "This native mill launcher supports only Linux and macOS." 1>&2
+     exit 1
+  fi
+}
+
+case "$MILL_VERSION" in
+    *"$MILL_NATIVE_SUFFIX")
+  MILL_VERSION=${MILL_VERSION%"$MILL_NATIVE_SUFFIX"}
+  set_artifact_suffix
+  ;;
+
+    *"$MILL_JVM_SUFFIX")
+    MILL_VERSION=${MILL_VERSION%"$MILL_JVM_SUFFIX"}
+  ;;
+
+    *)
+  case "$MILL_VERSION" in
+    0.1.*) ;;
+    0.2.*) ;;
+    0.3.*) ;;
+    0.4.*) ;;
+    0.5.*) ;;
+    0.6.*) ;;
+    0.7.*) ;;
+    0.8.*) ;;
+    0.9.*) ;;
+    0.10.*) ;;
+    0.11.*) ;;
+    0.12.*) ;;
+    *)
+      set_artifact_suffix
+  esac
+  ;;
+esac
+
+MILL="${MILL_DOWNLOAD_PATH}/$MILL_VERSION$ARTIFACT_SUFFIX"
+
+try_to_use_system_mill() {
+  if [ "$(uname)" != "Linux" ]; then
+    return 0
+  fi
+
+  MILL_IN_PATH="$(command -v mill || true)"
+
+  if [ -z "${MILL_IN_PATH}" ]; then
+    return 0
+  fi
+
+  SYSTEM_MILL_FIRST_TWO_BYTES=$(head --bytes=2 "${MILL_IN_PATH}")
+  if [ "${SYSTEM_MILL_FIRST_TWO_BYTES}" = "#!" ]; then
+	  # MILL_IN_PATH is (very likely) a shell script and not the mill
+	  # executable, ignore it.
+	  return 0
+  fi
+
+  SYSTEM_MILL_PATH=$(readlink -e "${MILL_IN_PATH}")
+  SYSTEM_MILL_SIZE=$(stat --format=%s "${SYSTEM_MILL_PATH}")
+  SYSTEM_MILL_MTIME=$(stat --format=%y "${SYSTEM_MILL_PATH}")
+
+  if [ ! -d "${MILL_USER_CACHE_DIR}" ]; then
+    mkdir -p "${MILL_USER_CACHE_DIR}"
+  fi
+
+  SYSTEM_MILL_INFO_FILE="${MILL_USER_CACHE_DIR}/system-mill-info"
+  if [ -f "${SYSTEM_MILL_INFO_FILE}" ]; then
+    parseSystemMillInfo() {
+        LINE_NUMBER="${1}"
+        # Select the line number of the SYSTEM_MILL_INFO_FILE, cut the
+        # variable definition in that line in two halves and return
+        # the value, and finally remove the quotes.
+        sed -n "${LINE_NUMBER}p" "${SYSTEM_MILL_INFO_FILE}" |\
+            cut -d= -f2 |\
+            sed 's/"\(.*\)"/\1/'
+    }
+
+    CACHED_SYSTEM_MILL_PATH=$(parseSystemMillInfo 1)
+    CACHED_SYSTEM_MILL_VERSION=$(parseSystemMillInfo 2)
+    CACHED_SYSTEM_MILL_SIZE=$(parseSystemMillInfo 3)
+    CACHED_SYSTEM_MILL_MTIME=$(parseSystemMillInfo 4)
+
+    if [ "${SYSTEM_MILL_PATH}" = "${CACHED_SYSTEM_MILL_PATH}" ] \
+           && [ "${SYSTEM_MILL_SIZE}" = "${CACHED_SYSTEM_MILL_SIZE}" ] \
+           && [ "${SYSTEM_MILL_MTIME}" = "${CACHED_SYSTEM_MILL_MTIME}" ]; then
+      if [ "${CACHED_SYSTEM_MILL_VERSION}" = "${MILL_VERSION}" ]; then
+          MILL="${SYSTEM_MILL_PATH}"
+          return 0
+      else
+          return 0
+      fi
+    fi
+  fi
+
+  SYSTEM_MILL_VERSION=$(${SYSTEM_MILL_PATH} --version | head -n1 | sed -n 's/^Mill.*version \(.*\)/\1/p')
+
+  cat <<EOF > "${SYSTEM_MILL_INFO_FILE}"
+CACHED_SYSTEM_MILL_PATH="${SYSTEM_MILL_PATH}"
+CACHED_SYSTEM_MILL_VERSION="${SYSTEM_MILL_VERSION}"
+CACHED_SYSTEM_MILL_SIZE="${SYSTEM_MILL_SIZE}"
+CACHED_SYSTEM_MILL_MTIME="${SYSTEM_MILL_MTIME}"
+EOF
+
+  if [ "${SYSTEM_MILL_VERSION}" = "${MILL_VERSION}" ]; then
+    MILL="${SYSTEM_MILL_PATH}"
+  fi
+}
+try_to_use_system_mill
+
+# If not already downloaded, download it
+if [ ! -s "${MILL}" ] || [ "$MILL_TEST_DRY_RUN_LAUNCHER_SCRIPT" = "1" ] ; then
+  case $MILL_VERSION in
+    0.0.* | 0.1.* | 0.2.* | 0.3.* | 0.4.* )
+      DOWNLOAD_SUFFIX=""
+      DOWNLOAD_FROM_MAVEN=0
+      ;;
+    0.5.* | 0.6.* | 0.7.* | 0.8.* | 0.9.* | 0.10.* | 0.11.0-M* )
+      DOWNLOAD_SUFFIX="-assembly"
+      DOWNLOAD_FROM_MAVEN=0
+      ;;
+    *)
+      DOWNLOAD_SUFFIX="-assembly"
+      DOWNLOAD_FROM_MAVEN=1
+      ;;
+  esac
+  case $MILL_VERSION in
+    0.12.0 | 0.12.1 | 0.12.2 | 0.12.3 | 0.12.4 | 0.12.5 | 0.12.6 | 0.12.7 | 0.12.8 | 0.12.9 | 0.12.10 | 0.12.11 )
+      DOWNLOAD_EXT="jar"
+      ;;
+    0.12.* )
+      DOWNLOAD_EXT="exe"
+      ;;
+    0.* )
+      DOWNLOAD_EXT="jar"
+      ;;
+    *)
+      DOWNLOAD_EXT="exe"
+      ;;
+  esac
+
+  DOWNLOAD_FILE=$(mktemp mill.XXXXXX)
+  if [ "$DOWNLOAD_FROM_MAVEN" = "1" ] ; then
+    DOWNLOAD_URL="https://repo1.maven.org/maven2/com/lihaoyi/mill-dist${ARTIFACT_SUFFIX}/${MILL_VERSION}/mill-dist${ARTIFACT_SUFFIX}-${MILL_VERSION}.${DOWNLOAD_EXT}"
+  else
+    MILL_VERSION_TAG=$(echo "$MILL_VERSION" | sed -E 's/([^-]+)(-M[0-9]+)?(-.*)?/\1\2/')
+    DOWNLOAD_URL="${GITHUB_RELEASE_CDN}${MILL_REPO_URL}/releases/download/${MILL_VERSION_TAG}/${MILL_VERSION}${DOWNLOAD_SUFFIX}"
+    unset MILL_VERSION_TAG
+  fi
+
+  if [ "$MILL_TEST_DRY_RUN_LAUNCHER_SCRIPT" = "1" ] ; then
+    echo $DOWNLOAD_URL
+    echo $MILL
+    exit 0
+  fi
+  # TODO: handle command not found
+  echo "Downloading mill ${MILL_VERSION} from ${DOWNLOAD_URL} ..." 1>&2
+  ${CURL_CMD} -f -L -o "${DOWNLOAD_FILE}" "${DOWNLOAD_URL}"
+  chmod +x "${DOWNLOAD_FILE}"
+  mkdir -p "${MILL_DOWNLOAD_PATH}"
+  mv "${DOWNLOAD_FILE}" "${MILL}"
+
+  unset DOWNLOAD_FILE
+  unset DOWNLOAD_SUFFIX
+fi
+
+if [ -z "$MILL_MAIN_CLI" ] ; then
+  MILL_MAIN_CLI="${0}"
+fi
+
+MILL_FIRST_ARG=""
+if [ "$1" = "--bsp" ] || [ "$1" = "-i" ] || [ "$1" = "--interactive" ] || [ "$1" = "--no-server" ] || [ "$1" = "--repl" ] || [ "$1" = "--help" ] ; then
+  # Need to preserve the first position of those listed options
+  MILL_FIRST_ARG=$1
+  shift
+fi
+
+unset MILL_DOWNLOAD_PATH
+unset MILL_OLD_DOWNLOAD_PATH
+unset OLD_MILL
+unset MILL_VERSION
+unset MILL_REPO_URL
+
+# -D mill.main.cli is for compatibility with Mill 0.10.9 - 0.13.0-M2
+# We don't quote MILL_FIRST_ARG on purpose, so we can expand the empty value without quotes
+# shellcheck disable=SC2086
+exec "${MILL}" $MILL_FIRST_ARG -D "mill.main.cli=${MILL_MAIN_CLI}" "$@"
diff --git a/src/test/java/com/github/tonivade/vavr/effect/ScheduleTest.java b/src/test/java/com/github/tonivade/vavr/effect/ScheduleTest.java
index f639b59..d8f7da3 100644
--- a/src/test/java/com/github/tonivade/vavr/effect/ScheduleTest.java
+++ b/src/test/java/com/github/tonivade/vavr/effect/ScheduleTest.java
@@ -14,6 +14,8 @@
 import java.time.Duration;
 import java.util.function.Consumer;
 import java.util.function.Supplier;
+
+import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.ExtendWith;
 import org.mockito.Mock;
@@ -36,6 +38,8 @@
 
     assertEquals(unit(), result);
     verify(console, times(3)).accept("hola");
+
+    Assertions.fail();
   }
 
   @Test