diff --git a/compiler/src/dotty/tools/dotc/CompilationUnit.scala b/compiler/src/dotty/tools/dotc/CompilationUnit.scala
index 078aa6c27635..b796b6c3cb5b 100644
--- a/compiler/src/dotty/tools/dotc/CompilationUnit.scala
+++ b/compiler/src/dotty/tools/dotc/CompilationUnit.scala
@@ -131,12 +131,12 @@ object CompilationUnit {
     unit1
   }
 
-  /** Create a compilation unit corresponding to an in-memory String. 
+  /** Create a compilation unit corresponding to an in-memory String.
    *  Used for `compiletime.testing.typeChecks`.
    */
   def apply(name: String, source: String)(using Context): CompilationUnit = {
     val src = SourceFile.virtual(name = name, content = source, maybeIncomplete = false)
-    new CompilationUnit(src, null)
+    new CompilationUnit(src)
   }
 
   /** Create a compilation unit corresponding to `source`.
diff --git a/compiler/src/dotty/tools/dotc/core/Phases.scala b/compiler/src/dotty/tools/dotc/core/Phases.scala
index 2f4bdc9f3d01..8d690a28a403 100644
--- a/compiler/src/dotty/tools/dotc/core/Phases.scala
+++ b/compiler/src/dotty/tools/dotc/core/Phases.scala
@@ -210,7 +210,7 @@ object Phases {
     private var myPostTyperPhase: Phase = _
     private var mySbtExtractDependenciesPhase: Phase = _
     private var myPicklerPhase: Phase = _
-    private var mySetRootTreePhase: Phase = uninitialized
+    private var mySetRootTreePhase: Phase = _
     private var myInliningPhase: Phase = _
     private var myStagingPhase: Phase = _
     private var mySplicingPhase: Phase = _
diff --git a/compiler/test-resources/repl/init-script-flag b/compiler/test-resources/repl/init-script-flag
new file mode 100644
index 000000000000..373f21e15e93
--- /dev/null
+++ b/compiler/test-resources/repl/init-script-flag
@@ -0,0 +1,5 @@
+scala>:reset --repl-init-script:'println("Hello from init script!")'
+Resetting REPL state with the following settings:
+  --repl-init-script:println("Hello from init script!")
+
+Hello from init script!
diff --git a/tests/neg/i22320.check b/tests/neg/i22320.check
deleted file mode 100644
index 3bada9a0b73c..000000000000
--- a/tests/neg/i22320.check
+++ /dev/null
@@ -1,12 +0,0 @@
--- [E008] Not Found Error: tests/neg/i22320.scala:19:19 ----------------------------------------------------------------
-19 |    val z = system.z // error
-   |            ^^^^^^^^
-   |            value z is not a member of a.System.
-   |            An extension method was tried, but could not be fully constructed:
-   |
-   |                a.z(system)
-   |
-   |                failed with:
-   |
-   |                    Found:    (system : a.System)
-   |                    Required: a.SimulatedSystem
diff --git a/tests/neg/i22320.scala b/tests/neg/i22320.scala
deleted file mode 100644
index 4a9eccf08474..000000000000
--- a/tests/neg/i22320.scala
+++ /dev/null
@@ -1,19 +0,0 @@
-package a:
-  opaque type System = Any
-  opaque type SimulatedSystem <: System = System
-
-  extension (system: System)
-    def x: BigInt = ???
-    def y: BigInt = ???
-  end extension
-
-  extension (system: SimulatedSystem)
-    def z: BigInt = ???
-  end extension
-
-package b:
-  import a.*
-  def issue(system: System) =
-    val x = system.x
-    val y = system.y
-    val z = system.z // error
\ No newline at end of file