diff --git a/libc/runtime/zipos-open.c b/libc/runtime/zipos-open.c
index 5253c40e1..0f04e2310 100644
--- a/libc/runtime/zipos-open.c
+++ b/libc/runtime/zipos-open.c
@@ -31,8 +31,10 @@
 #include "libc/intrin/cmpxchg.h"
 #include "libc/intrin/directmap.internal.h"
 #include "libc/intrin/extend.internal.h"
+#include "libc/intrin/likely.h"
 #include "libc/intrin/strace.internal.h"
 #include "libc/intrin/weaken.h"
+#include "libc/limits.h"
 #include "libc/runtime/internal.h"
 #include "libc/runtime/memtrack.internal.h"
 #include "libc/runtime/zipos.internal.h"
@@ -49,6 +51,8 @@
 #include "libc/thread/tls.h"
 #include "libc/zip.internal.h"
 
+#define MAX_REFS (INT_MAX >> 1)
+
 static char *__zipos_mapend;
 static size_t __zipos_maptotal;
 static pthread_mutex_t __zipos_lock_obj;
@@ -79,13 +83,17 @@ static void *__zipos_mmap_space(size_t mapsize) {
 }
 
 struct ZiposHandle *__zipos_keep(struct ZiposHandle *h) {
-  atomic_fetch_add_explicit(&h->refs, 1, memory_order_relaxed);
+  int refs = atomic_fetch_add_explicit(&h->refs, 1, memory_order_relaxed);
+  unassert(!VERY_UNLIKELY(refs > MAX_REFS));
   return h;
 }
 
 static bool __zipos_drop(struct ZiposHandle *h) {
-  int refs = atomic_load_explicit(&h->refs, memory_order_acquire);
-  return -1 == refs || -1 == atomic_fetch_sub(&h->refs, 1);
+  if (!atomic_fetch_sub_explicit(&h->refs, 1, memory_order_release)) {
+    atomic_thread_fence(memory_order_acquire);
+    return true;
+  }
+  return false;
 }
 
 void __zipos_free(struct ZiposHandle *h) {
@@ -113,7 +121,7 @@ StartOver:
   while ((h = *ph)) {
     if (h->mapsize >= mapsize) {
       if (!_cmpxchg(ph, h, h->next)) goto StartOver;
-      atomic_init(&h->refs, 0);
+      atomic_store_explicit(&h->refs, 0, memory_order_relaxed);
       break;
     }
     ph = &h->next;