diff --git a/acinclude.m4 b/acinclude.m4
index 491769a5f..6a192ea24 100644
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -87,27 +87,6 @@ int main() {
   [AC_MSG_RESULT(cross-compiling -- assuming yes); $3])
 ])
 
-dnl Checks if PCAP_NETMASK_UNKNOWN is defined (has been since libpcap 1.1.1)
-dnl Sets it to 0 (no checking) if it's not defined.
-AC_DEFUN([PCAP_DEFINE_NETMASK_UNKNOWN],
-[
-  AC_MSG_CHECKING(if PCAP_NETMASK_UNKNOWN is defined/handled by libpcap)
-  AC_CACHE_VAL(ac_cv_have_pcap_netmask_unknown,
-    AC_TRY_COMPILE(
-      [
-      #include <pcap.h>
-      ],
-      [
-      int i = PCAP_NETMASK_UNKNOWN;
-      ],
-      ac_cv_have_pcap_netmask_unknown=yes,
-      ac_cv_have_pcap_netmask_unknown=no))
-  if test $ac_cv_have_pcap_netmask_unknown = no; then
-    AC_DEFINE(PCAP_NETMASK_UNKNOWN, 0, [Possibly using libpcap prior to 1.1.0.])
-  fi
-  AC_MSG_RESULT($ac_cv_have_pcap_netmask_unknown)
-])
-
 dnl Checks if IPPROTO_RAW induces IP_HDRINCL-like behavior in AF_INET6 sockets.
 dnl Defines HAVE_IPV6_IPPROTO_RAW if so. So far I only know this happens on
 dnl Linux.
diff --git a/configure b/configure
index 79a10e770..9df1bc28a 100755
--- a/configure
+++ b/configure
@@ -6380,43 +6380,7 @@ else
   # link with -lpcap for the purposes of this test
   LIBS_OLD="$LIBS"
   LIBS="$LIBS -lpcap"
-
-  { $as_echo "$as_me:${as_lineno-$LINENO}: checking if PCAP_NETMASK_UNKNOWN is defined/handled by libpcap" >&5
-$as_echo_n "checking if PCAP_NETMASK_UNKNOWN is defined/handled by libpcap... " >&6; }
-  if ${ac_cv_have_pcap_netmask_unknown+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-
-      #include <pcap.h>
-
-int
-main ()
-{
-
-      int i = PCAP_NETMASK_UNKNOWN;
-
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_c_try_compile "$LINENO"; then :
-  ac_cv_have_pcap_netmask_unknown=yes
-else
-  ac_cv_have_pcap_netmask_unknown=no
-fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
-fi
-
-  if test $ac_cv_have_pcap_netmask_unknown = no; then
-
-$as_echo "#define PCAP_NETMASK_UNKNOWN 0" >>confdefs.h
-
-  fi
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_have_pcap_netmask_unknown" >&5
-$as_echo "$ac_cv_have_pcap_netmask_unknown" >&6; }
-
+  PCAP_DEFINE_NETMASK_UNKNOWN
   for ac_func in pcap_set_immediate_mode
 do :
   ac_fn_c_check_func "$LINENO" "pcap_set_immediate_mode" "ac_cv_func_pcap_set_immediate_mode"
diff --git a/libnetutil/netutil.cc b/libnetutil/netutil.cc
index 8e082424c..2527ea296 100644
--- a/libnetutil/netutil.cc
+++ b/libnetutil/netutil.cc
@@ -206,6 +206,11 @@
 
 #define NBASE_MAX_ERR_STR_LEN 1024  /* Max length of an error message */
 
+#ifndef PCAP_NETMASK_UNKNOWN
+/* libpcap before 1.1.1 (e.g. WinPcap) doesn't handle this specially, so just use 0 netmask */
+#define PCAP_NETMASK_UNKNOWN 0
+#endif
+
 /** Print fatal error messages to stderr and then exits. A newline
     character is printed automatically after the supplied text.
  * @warning This function does not return because it calls exit() */
diff --git a/nmap_config.h.in b/nmap_config.h.in
index 524ff7437..ead0007d8 100644
--- a/nmap_config.h.in
+++ b/nmap_config.h.in
@@ -254,7 +254,6 @@ extern "C" int gethostname (char *, unsigned int);
 #undef MACOSX
 
 #undef HAVE_IPV6_IPPROTO_RAW
-#undef PCAP_NETMASK_UNKNOWN
 #undef HAVE_PCAP_SET_IMMEDIATE_MODE
 
 /* Various possibilities for lua.h */
diff --git a/nse_pcrelib.cc b/nse_pcrelib.cc
index adc52c68f..9f6a72dc0 100644
--- a/nse_pcrelib.cc
+++ b/nse_pcrelib.cc
@@ -11,8 +11,7 @@
 
 #include <locale.h>
 
-#include "nbase.h"
-#include "nmap_error.h"
+#include <nbase.h>
 
 #ifdef HAVE_PCRE_PCRE_H
 # include <pcre/pcre.h>
diff --git a/nsock/include/nsock_config.h.in b/nsock/include/nsock_config.h.in
index ee9c0206e..33883488d 100644
--- a/nsock/include/nsock_config.h.in
+++ b/nsock/include/nsock_config.h.in
@@ -89,5 +89,4 @@
 #undef HAVE_POLL
 #undef HAVE_KQUEUE
 
-#undef PCAP_NETMASK_UNKNOWN
 #undef HAVE_PCAP_SET_IMMEDIATE_MODE
diff --git a/nsock/src/acinclude.m4 b/nsock/src/acinclude.m4
index 696cd3414..fc096648c 100644
--- a/nsock/src/acinclude.m4
+++ b/nsock/src/acinclude.m4
@@ -117,25 +117,3 @@ AC_DEFUN([AX_HAVE_POLL], [dnl
 $1],[AC_MSG_RESULT([no])
 $2])
 ])dnl
-
-dnl Checks if PCAP_NETMASK_UNKNOWN is defined (has been since libpcap 1.1.1)
-dnl Sets it to 0 (no checking) if it's not defined.
-AC_DEFUN([PCAP_DEFINE_NETMASK_UNKNOWN],
-[
-  AC_MSG_CHECKING(if PCAP_NETMASK_UNKNOWN is defined/handled by libpcap)
-  AC_CACHE_VAL(ac_cv_have_pcap_netmask_unknown,
-    AC_TRY_COMPILE(
-      [
-      #include <pcap.h>
-      ],
-      [
-      int i = PCAP_NETMASK_UNKNOWN;
-      ],
-      ac_cv_have_pcap_netmask_unknown=yes,
-      ac_cv_have_pcap_netmask_unknown=no))
-  if test $ac_cv_have_pcap_netmask_unknown = no; then
-    AC_DEFINE(PCAP_NETMASK_UNKNOWN, 0, [Possibly using libpcap prior to 1.1.0.])
-  fi
-  AC_MSG_RESULT($ac_cv_have_pcap_netmask_unknown)
-])
-
diff --git a/nsock/src/configure b/nsock/src/configure
index 954f68769..55c812261 100755
--- a/nsock/src/configure
+++ b/nsock/src/configure
@@ -3672,43 +3672,7 @@ $as_echo "#define HAVE_PCAP 1" >>confdefs.h
 fi
 
 
-
-  { $as_echo "$as_me:${as_lineno-$LINENO}: checking if PCAP_NETMASK_UNKNOWN is defined/handled by libpcap" >&5
-$as_echo_n "checking if PCAP_NETMASK_UNKNOWN is defined/handled by libpcap... " >&6; }
-  if ${ac_cv_have_pcap_netmask_unknown+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-
-      #include <pcap.h>
-
-int
-main ()
-{
-
-      int i = PCAP_NETMASK_UNKNOWN;
-
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_c_try_compile "$LINENO"; then :
-  ac_cv_have_pcap_netmask_unknown=yes
-else
-  ac_cv_have_pcap_netmask_unknown=no
-fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
-fi
-
-  if test $ac_cv_have_pcap_netmask_unknown = no; then
-
-$as_echo "#define PCAP_NETMASK_UNKNOWN 0" >>confdefs.h
-
-  fi
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_have_pcap_netmask_unknown" >&5
-$as_echo "$ac_cv_have_pcap_netmask_unknown" >&6; }
-
+PCAP_DEFINE_NETMASK_UNKNOWN
 
   ax_have_epoll_cppflags="${CPPFLAGS}"
   ac_fn_c_check_header_mongrel "$LINENO" "linux/version.h" "ac_cv_header_linux_version_h" "$ac_includes_default"
diff --git a/nsock/src/nsock_pcap.c b/nsock/src/nsock_pcap.c
index 554510d1b..9f9ae2bf0 100644
--- a/nsock/src/nsock_pcap.c
+++ b/nsock/src/nsock_pcap.c
@@ -81,6 +81,11 @@ extern struct timeval nsock_tod;
 
 #if HAVE_PCAP
 
+#ifndef PCAP_NETMASK_UNKNOWN
+/* libpcap before 1.1.1 (e.g. WinPcap) doesn't handle this specially, so just use 0 netmask */
+#define PCAP_NETMASK_UNKNOWN 0
+#endif
+
 #define PCAP_OPEN_MAX_RETRIES   3
 
 #define PCAP_FAILURE_EXPL_MESSAGE  \
diff --git a/nsock/src/nsock_pcap.h b/nsock/src/nsock_pcap.h
index 395d99098..ed754795d 100644
--- a/nsock/src/nsock_pcap.h
+++ b/nsock/src/nsock_pcap.h
@@ -66,13 +66,6 @@
 #include <string.h>
 #include <stdarg.h>
 
-#ifdef WIN32
-/* WinPCAP doesn't have this, but Npcap does.
- * Using 0 is safe for both, but change this if we decide to drop WinPcap */
-#undef PCAP_NETMASK_UNKNOWN
-#define PCAP_NETMASK_UNKNOWN 0
-#endif
-
 /*
  * There are three possible ways to read packets from pcap descriptor:
  *  - select() on descriptor:
diff --git a/tcpip.h b/tcpip.h
index 3ac7ba8f6..939b0d969 100644
--- a/tcpip.h
+++ b/tcpip.h
@@ -138,12 +138,6 @@
 #include "nbase.h"
 
 #include <pcap.h>
-#ifdef WIN32
-/* WinPCAP doesn't have this, but Npcap does.
- * Using 0 is safe for both, but change this if we decide to drop WinPcap */
-#undef PCAP_NETMASK_UNKNOWN
-#define PCAP_NETMASK_UNKNOWN 0
-#endif
 
 class Target;