diff --git a/ffi/alloc.nim b/ffi/alloc.nim
index 69c5340..a841a8f 100644
--- a/ffi/alloc.nim
+++ b/ffi/alloc.nim
@@ -25,8 +25,11 @@ proc alloc*(str: string): cstring =
 
 proc allocSharedSeq*[T](s: seq[T]): SharedSeq[T] =
   let data = allocShared(sizeof(T) * s.len)
-  if s.len != 0:
-    copyMem(data, unsafeAddr s[0], sizeof(T) * s.len)
+
+  if s.len == 0:
+    return (cast[ptr UncheckedArray[T]](nil), 0)
+
+  copyMem(data, unsafeAddr s[0], sizeof(T) * s.len)
   return (cast[ptr UncheckedArray[T]](data), s.len)
 
 proc deallocSharedSeq*[T](s: var SharedSeq[T]) =