diff --git a/lib/system/gc.nim b/lib/system/gc.nim
index 66a5df73cb..e37f601b43 100644
--- a/lib/system/gc.nim
+++ b/lib/system/gc.nim
@@ -593,6 +593,7 @@ proc growObj(old: pointer, newsize: int, gch: var GcHeap): pointer =
             break
           dec(j)
       beforeDealloc(gch, ol, "growObj stack trash")
+      decTypeSize(ol, ol.typ)
       rawDealloc(gch.region, ol)
     else:
       # we split the old refcount in 2 parts. XXX This is still not entirely