diff --git a/lib/core/seqs.nim b/lib/core/seqs.nim
index 1a81b89ea0..20ea9e0351 100644
--- a/lib/core/seqs.nim
+++ b/lib/core/seqs.nim
@@ -43,7 +43,8 @@ proc `=destroy`[T](s: var seq[T]) =
     mixin `=destroy`
     when not supportsCopyMem(T):
       for i in 0..<x.len: `=destroy`(p.data[i])
-    p.region.dealloc(p.region, p, payloadSize(p.cap))
+    if p.region != nil:
+      p.region.dealloc(p.region, p, payloadSize(p.cap))
     x.p = nil
     x.len = 0