1 files changed, 14 insertions, 0 deletions
diff --git a/tests/notnil/tmust_compile.nim b/tests/notnil/tmust_compile.nim
index 117921a57..10da154f0 100644
--- a/tests/notnil/tmust_compile.nim
+++ b/tests/notnil/tmust_compile.nim
@@ -62,3 +62,17 @@ proc parse(cts: CTS, jn: JsonNode) =
 
 proc p(x: proc(){.closure.} not nil) = discard
 p(proc(){.closure.} = discard)
+
+# bug #3993
+
+type
+  List[T] = seq[T] not nil
+
+proc `^^`[T](v: T, lst: List[T]): List[T] =
+  result = @[v]
+  result.add(lst)
+
+proc Nil[T](): List[T] = @[]
+
+when isMainModule:
+  let lst = 1 ^^ 2 ^^ Nil[int]()