diff --git a/lib/system.nim b/lib/system.nim
index 15346b135f..32a88de64f 100644
--- a/lib/system.nim
+++ b/lib/system.nim
@@ -106,6 +106,8 @@ type
   SomeNumber* = SomeInteger|SomeFloat
     ## type class matching all number types
 
+{.deprecated: [SomeReal: SomeFloat].}
+
 proc defined*(x: untyped): bool {.magic: "Defined", noSideEffect, compileTime.}
   ## Special compile-time procedure that checks whether `x` is
   ## defined.