diff --git a/lib/system/mmdisp.nim b/lib/system/mmdisp.nim
index 9af36c7b8c..d65d8a10ed 100644
--- a/lib/system/mmdisp.nim
+++ b/lib/system/mmdisp.nim
@@ -571,3 +571,11 @@ when not declared(nimNewSeqOfCap):
     cast[PGenericSeq](result).reserved = cap
 
 {.pop.}
+
+when not declared(ForeignCell):
+  type ForeignCell* = object
+    data*: pointer
+
+  proc protect*(x: pointer): ForeignCell = ForeignCell(data: x)
+  proc dispose*(x: ForeignCell) = discard
+  proc isNotForeign*(x: ForeignCell): bool = false