diff --git a/.mill-version b/.mill-version
index 5746d36d5..ac454c6a1 100644
--- a/.mill-version
+++ b/.mill-version
@@ -1 +1 @@
-0.11.12
\ No newline at end of file
+0.12.0
diff --git a/build.sc b/build.sc
index 3763f887a..cac003c33 100644
--- a/build.sc
+++ b/build.sc
@@ -190,6 +190,8 @@ trait AmmInternalModule extends CrossSbtModule with Bloop.Module {
   trait AmmTests extends super.Tests with TestModule.Utest {
     def ivyDeps = super.ivyDeps() ++ Agg(Deps.utest)
     def forkArgs = Seq("-Xmx2g", "-Dfile.encoding=UTF8")
+    def testForkGrouping = discoveredTestClasses().grouped(1).toSeq
+    def testSandboxWorkingDir = false
   }
   def allBoundIvyDeps = T { transitiveIvyDeps() ++ scalaLibraryIvyDeps().map(bindDependency()) }
   def sources = T.sources {
@@ -909,6 +911,7 @@ def publishDocs(skipDeploy: Boolean = false): Command[Unit] = {
         "sbt",
         "readme/run"
       ).call(
+        cwd = T.workspace,
         env = Map(
           "AMMONITE_ASSEMBLY" -> ammoniteAssembly().path.toString,
           "CONSTANTS_FILE" -> generateConstantsFile(returnDirectory = false).toString
@@ -969,6 +972,7 @@ def publishDocs(skipDeploy: Boolean = false): Command[Unit] = {
       "sbt",
       "readme/run"
     ).call(
+      cwd = T.workspace,
       env = Map(
         "AMMONITE_ASSEMBLY" -> ammoniteAssembly().path.toString,
         "CONSTANTS_FILE" -> constantsFile.toString
diff --git a/mill b/mill
index d400d4288..d03a045cb 100755
--- a/mill
+++ b/mill
@@ -3,10 +3,13 @@
 # This is a wrapper script, that automatically download mill from GitHub release pages
 # You can give the required mill version with MILL_VERSION env variable
 # If no version is given, it falls back to the value of DEFAULT_MILL_VERSION
-DEFAULT_MILL_VERSION=0.10.7
 
 set -e
 
+if [ -z "${DEFAULT_MILL_VERSION}" ] ; then
+  DEFAULT_MILL_VERSION=0.11.12
+fi
+
 if [ -z "$MILL_VERSION" ] ; then
   if [ -f ".mill-version" ] ; then
     MILL_VERSION="$(head -n 1 .mill-version 2> /dev/null)"
@@ -37,7 +40,7 @@ if [ ! -s "$MILL_EXEC_PATH" ] ; then
   fi
   DOWNLOAD_FILE=$MILL_EXEC_PATH-tmp-download
   MILL_VERSION_TAG=$(echo $MILL_VERSION | sed -E 's/([^-]+)(-M[0-9]+)?(-.*)?/\1\2/')
-  MILL_DOWNLOAD_URL="https://github.com/lihaoyi/mill/releases/download/${MILL_VERSION_TAG}/$MILL_VERSION${ASSEMBLY}"
+  MILL_DOWNLOAD_URL="https://repo1.maven.org/maven2/com/lihaoyi/mill-dist/$MILL_VERSION/mill-dist-$MILL_VERSION.jar"
   curl --fail -L -o "$DOWNLOAD_FILE" "$MILL_DOWNLOAD_URL"
   chmod +x "$DOWNLOAD_FILE"
   mv "$DOWNLOAD_FILE" "$MILL_EXEC_PATH"
@@ -45,7 +48,20 @@ if [ ! -s "$MILL_EXEC_PATH" ] ; then
   unset MILL_DOWNLOAD_URL
 fi
 
+if [ -z "$MILL_MAIN_CLI" ] ; then
+  MILL_MAIN_CLI="${0}"
+fi
+
+MILL_FIRST_ARG=""
+
+ # first arg is a long flag for "--interactive" or starts with "-i"
+if [ "$1" = "--bsp" ] || [ "${1#"-i"}" != "$1" ] || [ "$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_VERSION
 
-exec $MILL_EXEC_PATH "$@"
+exec $MILL_EXEC_PATH $MILL_FIRST_ARG -D "mill.main.cli=${MILL_MAIN_CLI}" "$@"