diff --git a/internal/util-collection/src/main/scala/sbt/internal/util/Util.scala b/internal/util-collection/src/main/scala/sbt/internal/util/Util.scala
index 8ec3636a6..ca03ed381 100644
--- a/internal/util-collection/src/main/scala/sbt/internal/util/Util.scala
+++ b/internal/util-collection/src/main/scala/sbt/internal/util/Util.scala
@@ -54,7 +54,7 @@ object Util {
     System.getProperty("os.name").toLowerCase(Locale.ENGLISH).contains("windows")
 
   lazy val isCygwin: Boolean = {
-    val os = Option(System.getenv("OSTYPE"))
+    val os = sys.env.get("OSTYPE")
     os match {
       case Some(x) => x.toLowerCase(Locale.ENGLISH).contains("cygwin")
       case _       => false
@@ -64,7 +64,7 @@ object Util {
   lazy val isNonCygwinWindows: Boolean = isWindows && !isCygwin
   lazy val isCygwinWindows: Boolean = isWindows && isCygwin
 
-  lazy val isEmacs: Boolean = Option(System.getenv("INSIDE_EMACS")).isDefined
+  lazy val isEmacs: Boolean = sys.env.contains("INSIDE_EMACS")
 
   def nil[A]: List[A] = List.empty[A]
   def nilSeq[A]: Seq[A] = Seq.empty[A]
diff --git a/internal/util-logging/src/main/scala/sbt/internal/util/Terminal.scala b/internal/util-logging/src/main/scala/sbt/internal/util/Terminal.scala
index 7fecdf0e5..9fa61c02e 100644
--- a/internal/util-logging/src/main/scala/sbt/internal/util/Terminal.scala
+++ b/internal/util-logging/src/main/scala/sbt/internal/util/Terminal.scala
@@ -308,7 +308,7 @@ object Terminal {
   }
   private[sbt] lazy val isAnsiSupported: Boolean = logFormatEnabled.getOrElse(useColorDefault)
 
-  private[this] val isDumb = "dumb" == System.getenv("TERM")
+  private[this] val isDumb = Some("dumb") == sys.env.get("TERM")
   private[this] def isDumbTerminal = isDumb || System.getProperty("jline.terminal", "") == "none"
   private[this] val hasConsole = Option(java.lang.System.console).isDefined
   private[this] def useColorDefault: Boolean = {
@@ -736,22 +736,20 @@ object Terminal {
       val supershell: Boolean
   )
   private[sbt] val TERMINAL_PROPS = "SBT_TERMINAL_PROPS"
-  private val props = System.getenv(TERMINAL_PROPS) match {
-    case null => None
-    case p =>
-      p.split(",") match {
-        case Array(width, height, ansi, color, supershell) =>
-          Try(
-            new Props(
-              width.toInt,
-              height.toInt,
-              ansi.toBoolean,
-              color.toBoolean,
-              supershell.toBoolean
-            )
-          ).toOption
-        case _ => None
-      }
+  private val props = sys.env.get(TERMINAL_PROPS) flatMap { p =>
+    p.split(",") match {
+      case Array(width, height, ansi, color, supershell) =>
+        Try(
+          new Props(
+            width.toInt,
+            height.toInt,
+            ansi.toBoolean,
+            color.toBoolean,
+            supershell.toBoolean
+          )
+        ).toOption
+      case _ => None
+    }
   }
   private[sbt] def startedByRemoteClient = props.isDefined
 
diff --git a/main-command/src/main/scala/sbt/internal/client/NetworkClient.scala b/main-command/src/main/scala/sbt/internal/client/NetworkClient.scala
index 8141376ac..71a11e6fd 100644
--- a/main-command/src/main/scala/sbt/internal/client/NetworkClient.scala
+++ b/main-command/src/main/scala/sbt/internal/client/NetworkClient.scala
@@ -139,7 +139,7 @@ class NetworkClient(
   private val rebooting = new AtomicBoolean(false)
   private lazy val noTab = arguments.completionArguments.contains("--no-tab")
   private lazy val noStdErr = arguments.completionArguments.contains("--no-stderr") &&
-    System.getenv("SBTC_AUTO_COMPLETE") == null
+    !sys.env.contains("SBTC_AUTO_COMPLETE")
 
   private def mkSocket(file: File): (Socket, Option[String]) = ClientSocket.socket(file, useJNI)
 
diff --git a/main/src/main/scala/sbt/Defaults.scala b/main/src/main/scala/sbt/Defaults.scala
index ec25047a0..facf6637a 100644
--- a/main/src/main/scala/sbt/Defaults.scala
+++ b/main/src/main/scala/sbt/Defaults.scala
@@ -148,6 +148,7 @@ object Defaults extends BuildCommon {
     val m = (for (a <- cp; an <- a.metadata get Keys.analysis) yield (a.data, an)).toMap
     m.get _
   }
+
   private[sbt] def globalDefaults(ss: Seq[Setting[_]]): Seq[Setting[_]] =
     Def.defaultSettings(inScope(GlobalScope)(ss))
 
@@ -229,7 +230,7 @@ object Defaults extends BuildCommon {
   private[sbt] lazy val globalIvyCore: Seq[Setting[_]] =
     Seq(
       internalConfigurationMap :== Configurations.internalMap _,
-      credentials :== Nil,
+      credentials :== SysProp.sbtCredentialsEnv.toList,
       exportJars :== false,
       trackInternalDependencies :== TrackLevel.TrackAlways,
       exportToInternal :== TrackLevel.TrackAlways,
diff --git a/main/src/main/scala/sbt/internal/SysProp.scala b/main/src/main/scala/sbt/internal/SysProp.scala
index c761e7f04..fbf0942b2 100644
--- a/main/src/main/scala/sbt/internal/SysProp.scala
+++ b/main/src/main/scala/sbt/internal/SysProp.scala
@@ -15,8 +15,9 @@ import scala.util.control.NonFatal
 import scala.concurrent.duration._
 import sbt.internal.util.{ Terminal => ITerminal, Util }
 import sbt.internal.util.complete.SizeParser
-import sbt.nio.Keys._
 import sbt.io.syntax._
+import sbt.librarymanagement.ivy.{ Credentials, FileCredentials }
+import sbt.nio.Keys._
 
 // See also BuildPaths.scala
 // See also LineReader.scala
@@ -216,4 +217,7 @@ object SysProp {
         .getOrElse(linuxCache)
     baseCache.getAbsoluteFile / "v1"
   }
+
+  val sbtCredentialsEnv: Option[Credentials] =
+    sys.env.get("SBT_CREDENTIALS").map(raw => new FileCredentials(new File(raw)))
 }
diff --git a/protocol/src/main/scala/sbt/internal/bsp/BuildServerConnection.scala b/protocol/src/main/scala/sbt/internal/bsp/BuildServerConnection.scala
index dc99a4973..66ac7bdf0 100644
--- a/protocol/src/main/scala/sbt/internal/bsp/BuildServerConnection.scala
+++ b/protocol/src/main/scala/sbt/internal/bsp/BuildServerConnection.scala
@@ -61,7 +61,7 @@ object BuildServerConnection {
     // For those who use an old sbt script, the -Dsbt.script is not set
     // As a fallback we try to find the sbt script in $PATH
     val fileName = if (Properties.isWin) "sbt.bat" else "sbt"
-    val envPath = Option(System.getenv("PATH")).getOrElse("")
+    val envPath = sys.env.getOrElse("PATH", "")
     val allPaths = envPath.split(File.pathSeparator).map(Paths.get(_))
     allPaths
       .map(_.resolve(fileName))
diff --git a/sbt-app/src/sbt-test/run/fork/src/main/scala/ForkFail.scala b/sbt-app/src/sbt-test/run/fork/src/main/scala/ForkFail.scala
index 847230c81..a1d489232 100644
--- a/sbt-app/src/sbt-test/run/fork/src/main/scala/ForkFail.scala
+++ b/sbt-app/src/sbt-test/run/fork/src/main/scala/ForkFail.scala
@@ -1,6 +1,6 @@
 object ForkTest {
   def main(args:Array[String]): Unit = {
-		val name = Option(System.getenv("flag.name")) getOrElse("flag")
+		val name = sys.env.getOrElse("flag.name", "flag")
 		println("Name: " + name)
 		val cwd = (new java.io.File(name)).getAbsoluteFile
 		cwd.getParentFile.mkdirs()
diff --git a/sbt-app/src/sbt-test/tests/fork2/changes/Test.scala b/sbt-app/src/sbt-test/tests/fork2/changes/Test.scala
index 6706da71f..f2d45c34f 100644
--- a/sbt-app/src/sbt-test/tests/fork2/changes/Test.scala
+++ b/sbt-app/src/sbt-test/tests/fork2/changes/Test.scala
@@ -1,7 +1,7 @@
 import org.scalatest.FlatSpec
 
 class Test extends FlatSpec {
-	val v = Option(System.getenv("tests.max.value")) getOrElse Int.MaxValue
+	val v = sys.env.getOrElse("tests.max.value", Int.MaxValue)
 	"A simple equation" should "hold" in {
 		assert(Int.MaxValue == v)
 	}