diff --git a/m-genint.h b/m-genint.h
index 3c7c6f21..a7e5b880 100644
--- a/m-genint.h
+++ b/m-genint.h
@@ -66,6 +66,8 @@ static inline void genint_init(genint_t s, size_t n)
     M_MEMORY_FULL(alloc);
     return;
   }
+  for(size_t i = 0; i < alloc; i++)
+    atomic_init(&s->data[i], 0);
   GENINT_CONTRACT(s);
 }