diff --git a/main-command/src/main/scala/sbt/Command.scala b/main-command/src/main/scala/sbt/Command.scala
index 9d9be7a33..6ee8e0e44 100644
--- a/main-command/src/main/scala/sbt/Command.scala
+++ b/main-command/src/main/scala/sbt/Command.scala
@@ -163,6 +163,16 @@ object Command {
           case Some(c) => c(state)
         })
 
+  def process(command: String, state: State): State = {
+    val parser = combine(state.definedCommands)
+    parse(command, parser(state)) match {
+      case Right(s) => s() // apply command.  command side effects happen here
+      case Left(errMsg) =>
+        state.log error errMsg
+        state.fail
+    }
+  }
+
   def invalidValue(label: String, allowed: Iterable[String])(value: String): String =
     s"Not a valid $label: $value" + similar(value, allowed)
 
diff --git a/main/src/main/scala/sbt/MainLoop.scala b/main/src/main/scala/sbt/MainLoop.scala
index 02897f7a0..e2c1fe0f2 100644
--- a/main/src/main/scala/sbt/MainLoop.scala
+++ b/main/src/main/scala/sbt/MainLoop.scala
@@ -17,7 +17,6 @@ import scala.util.control.NonFatal
 
 import sbt.io.{ IO, Using }
 import sbt.internal.util.{ ErrorHandling, GlobalLogBacking }
-import sbt.internal.util.complete.Parser
 import sbt.internal.langserver.ErrorCodes
 import sbt.util.Logger
 import sbt.protocol._
@@ -148,13 +147,7 @@ object MainLoop {
     val channelName = exec.source map (_.channelName)
     StandardMain.exchange publishEventMessage
       ExecStatusEvent("Processing", channelName, exec.execId, Vector())
-    val parser = Command combine state.definedCommands
-    val newState = Parser.parse(exec.commandLine, parser(state)) match {
-      case Right(s) => s() // apply command.  command side effects happen here
-      case Left(errMsg) =>
-        state.log error errMsg
-        state.fail
-    }
+    val newState = Command.process(exec.commandLine, state)
     val doneEvent = ExecStatusEvent(
       "Done",
       channelName,