diff --git a/scapy/libs/winpcapy.py b/scapy/libs/winpcapy.py
index 42bfa850921..17a0474a7fc 100644
--- a/scapy/libs/winpcapy.py
+++ b/scapy/libs/winpcapy.py
@@ -12,9 +12,10 @@
 from ctypes import *
 from ctypes.util import find_library
 import os
+import time
 
 from scapy.libs.structures import bpf_program
-from scapy.consts import WINDOWS, BSD
+from scapy.consts import WINDOWS, BSD, DARWIN, LINUX, NETBSD, OPENBSD
 
 if WINDOWS:
     # Try to load Npcap, or Winpcap
@@ -54,20 +55,50 @@
 FILE = c_void_p
 STRING = c_char_p
 
+try:
+    c_time_t  # Python 3.12+
+except NameError:
+    # Older Pythons: ask whether this build's time_t can hold 2**31
+    try:
+        time.gmtime(2 ** 31)
+        c_time_t = c_int64
+    except (OverflowError, OSError, ValueError):
+        c_time_t = c_int32
+
 
 class bpf_version(Structure):
     _fields_ = [("bv_major", c_ushort),
                 ("bv_minor", c_ushort)]
 
 
-class timeval(Structure):
-    _fields_ = [('tv_sec', c_long),
-                ('tv_usec', c_long)]
-
+# timeval has a different structure depending on the OS
+# - Windows uses two longs
+# - OpenBSD its own struct bpf_timeval of two u_int32_t
+# - Elsewhere its seconds are a time_t
+if WINDOWS:
+    # https://learn.microsoft.com/fr-fr/windows/win32/api/winsock/ns-winsock-timeval
+    class timeval(Structure):
+        _fields_ = [('tv_sec', c_long),
+                    ('tv_usec', c_long)]
+elif OPENBSD:
+    # https://github.com/openbsd/src/blob/a5d3ee8e660b7269f17fcd507a49e1e10ce52d58/sys/net/bpf.h#L143
+    class timeval(Structure):
+        _fields_ = [('tv_sec', c_uint32),
+                    ('tv_usec', c_uint32)]
+elif NETBSD or DARWIN:
+    class timeval(Structure):
+        _fields_ = [('tv_sec', c_time_t),
+                    ('tv_usec', c_int)]
+elif LINUX:
+    # As wide as tv_sec in glibc and musl, including glibc's 64-bit time
+    class timeval(Structure):
+        _fields_ = [('tv_sec', c_time_t),
+                    ('tv_usec', c_time_t)]
+else:
+    class timeval(Structure):
+        _fields_ = [('tv_sec', c_time_t),
+                    ('tv_usec', c_long)]
 
-# sockaddr is used by pcap_addr.
-# For example if sa_family==socket.AF_INET then we need cast
-# with sockaddr_in
 
 # sockaddr has a different structure depending on the OS
 if BSD: