4 files changed, 39 insertions, 9 deletions
diff --git a/compiler/src/dotty/tools/dotc/core/Flags.scala b/compiler/src/dotty/tools/dotc/core/Flags.scala
index c1267d8a2..29f1078a2 100644
--- a/compiler/src/dotty/tools/dotc/core/Flags.scala
+++ b/compiler/src/dotty/tools/dotc/core/Flags.scala
@@ -450,13 +450,22 @@ object Flags {
 
   /** Flags guaranteed to be set upon symbol creation */
   final val FromStartFlags =
-    AccessFlags | Module | Package | Deferred | Final | MethodOrHKCommon | Param | ParamAccessor | Scala2ExistentialCommon |
-    Mutable.toCommonFlags | InSuperCall | Touched | JavaStatic | CovariantOrOuter | ContravariantOrLabel | ExpandedName | AccessorOrSealed |
-    CaseAccessorOrBaseTypeArg | Fresh | Frozen | Erroneous | ImplicitCommon | Permanent | Synthetic |
-    Inline | LazyOrTrait | SuperAccessorOrScala2x | SelfNameOrImplClass
+    Module | Package | Deferred | MethodOrHKCommon | Param | ParamAccessor |
+    Scala2ExistentialCommon | Mutable.toCommonFlags | InSuperCall | Touched | JavaStatic |
+    CovariantOrOuter | ContravariantOrLabel | ExpandedName | CaseAccessorOrBaseTypeArg |
+    Fresh | Frozen | Erroneous | ImplicitCommon | Permanent | Synthetic |
+    SuperAccessorOrScala2x | Inline
+
+  /** Flags guaranteed to be set upon symbol creation, or, if symbol is a top-level
+   *  class or object, when the class file defining the symbol is loaded (which
+   *  is generally before the symbol is completed
+   */
+  final val AfterLoadFlags =
+    FromStartFlags | AccessFlags | Final | AccessorOrSealed | LazyOrTrait | SelfNameOrImplClass
 
   assert(FromStartFlags.isTermFlags && FromStartFlags.isTypeFlags)
   // TODO: Should check that FromStartFlags do not change in completion
+  assert(AfterLoadFlags.isTermFlags && AfterLoadFlags.isTypeFlags)
 
   /** A value that's unstable unless complemented with a Stable flag */
   final val UnstableValue = Mutable | Method
diff --git a/compiler/src/dotty/tools/dotc/core/SymDenotations.scala b/compiler/src/dotty/tools/dotc/core/SymDenotations.scala
index db96463e0..27782698d 100644
--- a/compiler/src/dotty/tools/dotc/core/SymDenotations.scala
+++ b/compiler/src/dotty/tools/dotc/core/SymDenotations.scala
@@ -163,26 +163,31 @@ object SymDenotations {
       setFlag(flags & mask)
     }
 
+    private def isCurrent(fs: FlagSet) =
+      fs <= (
+        if (myInfo.isInstanceOf[SymbolLoader]) FromStartFlags
+        else AfterLoadFlags)
+
     /** Has this denotation one of the flags in `fs` set? */
     final def is(fs: FlagSet)(implicit ctx: Context) = {
-      (if (fs <= FromStartFlags) myFlags else flags) is fs
+      (if (isCurrent(fs)) myFlags else flags) is fs
     }
 
     /** Has this denotation one of the flags in `fs` set, whereas none of the flags
      *  in `butNot` are set?
      */
     final def is(fs: FlagSet, butNot: FlagSet)(implicit ctx: Context) =
-      (if (fs <= FromStartFlags && butNot <= FromStartFlags) myFlags else flags) is (fs, butNot)
+      (if (isCurrent(fs) && isCurrent(butNot)) myFlags else flags) is (fs, butNot)
 
     /** Has this denotation all of the flags in `fs` set? */
     final def is(fs: FlagConjunction)(implicit ctx: Context) =
-      (if (fs <= FromStartFlags) myFlags else flags) is fs
+      (if (isCurrent(fs)) myFlags else flags) is fs
 
     /** Has this denotation all of the flags in `fs` set, whereas none of the flags
      *  in `butNot` are set?
      */
     final def is(fs: FlagConjunction, butNot: FlagSet)(implicit ctx: Context) =
-      (if (fs <= FromStartFlags && butNot <= FromStartFlags) myFlags else flags) is (fs, butNot)
+      (if (isCurrent(fs) && isCurrent(butNot)) myFlags else flags) is (fs, butNot)
 
     /** The type info.
      *  The info is an instance of TypeType iff this is a type denotation
diff --git a/compiler/src/dotty/tools/dotc/reporting/diagnostic/messages.scala b/compiler/src/dotty/tools/dotc/reporting/diagnostic/messages.scala
index 57365658e..b0f5f8ab1 100644
--- a/compiler/src/dotty/tools/dotc/reporting/diagnostic/messages.scala
+++ b/compiler/src/dotty/tools/dotc/reporting/diagnostic/messages.scala
@@ -238,7 +238,7 @@ object messages {
       import core.Flags._
       val maxDist = 3
       val decls = site.decls.flatMap { sym =>
-        if (sym.is(Synthetic | PrivateOrLocal) || sym.isConstructor) Nil
+        if (sym.flagsUNSAFE.is(Synthetic | PrivateOrLocal) || sym.isConstructor) Nil
         else List((sym.name.show, sym))
       }
 
diff --git a/tests/run/enum-Option.scala b/tests/run/enum-Option.scala
new file mode 100644
index 000000000..74e449daf
--- /dev/null
+++ b/tests/run/enum-Option.scala
@@ -0,0 +1,16 @@
+enum class Option[+T] extends Serializable {
+   def isDefined: Boolean
+}
+object Option {
+  case Some(x: T) {
+     def isDefined = true
+  }
+  case None extends Option[Nothing] {
+     def isDefined = false
+  }
+}
+
+object Test {
+  def main(args: Array[String]) =
+    assert(Some(None).isDefined)
+}