--- a/ipguard.c
+++ b/ipguard.c
@@ -29,6 +29,34 @@
 
 #include "ipguard.h"
 
+char iface[IFNAMSIZ];
+char ethers_name[PATH_MAX];
+char log_name[PATH_MAX];
+char pid_name[PATH_MAX];
+char fmac[18];
+char pcapf[PCAPFSIZ];
+char suser[MAXLOGNAME];
+int ethers_update;
+int fake_regen;
+int fake_num;
+int fake_time;
+int buffer_num;
+int addr_nosubst;
+int nofirst;
+int grant;
+int read_only;
+int duplex;
+int fixbc;
+int hidden;
+int promisc;
+int debug;
+int verbose;
+
+unsigned int all, good, grat, wgrat, zmac, zip, bad, bmac, bsip, btip,
+    bnew, bgrat, mymac, fake, pfake, nzh, nbe, mis;
+char pfmac[18];
+char s[128+1];
+
 void usage(char *name) {
     fprintf(stdout, "%s v%s (c) %s <%s>\n\n", NAME, VERSION, AUTHOR, MAIL);
     fprintf(stdout, "usage: %s [-h] [-ajgrxziovd]\n", name);
--- a/ipguard.h
+++ b/ipguard.h
@@ -68,33 +68,33 @@
 #define NOTICE          3
 #define INFO            4
 
-char iface[IFNAMSIZ];
-char ethers_name[PATH_MAX];
-char log_name[PATH_MAX];
-char pid_name[PATH_MAX];
-char fmac[18];
-char pcapf[PCAPFSIZ];
-char suser[MAXLOGNAME];
-int ethers_update;
-int fake_regen;
-int fake_num;
-int fake_time;
-int buffer_num;
-int addr_nosubst;
-int nofirst;
-int grant;
-int read_only;
-int duplex;
-int fixbc;
-int hidden;
-int promisc;
-int debug;
-int verbose;
+extern char iface[IFNAMSIZ];
+extern char ethers_name[PATH_MAX];
+extern char log_name[PATH_MAX];
+extern char pid_name[PATH_MAX];
+extern char fmac[18];
+extern char pcapf[PCAPFSIZ];
+extern char suser[MAXLOGNAME];
+extern int ethers_update;
+extern int fake_regen;
+extern int fake_num;
+extern int fake_time;
+extern int buffer_num;
+extern int addr_nosubst;
+extern int nofirst;
+extern int grant;
+extern int read_only;
+extern int duplex;
+extern int fixbc;
+extern int hidden;
+extern int promisc;
+extern int debug;
+extern int verbose;
 
-unsigned int all, good, grat, wgrat, zmac, zip, bad, bmac, bsip, btip,
+extern unsigned int all, good, grat, wgrat, zmac, zip, bad, bmac, bsip, btip,
     bnew, bgrat, mymac, fake, pfake, nzh, nbe, mis;
-char pfmac[18];
-char s[128+1];
+extern char pfmac[18];
+extern char s[128+1];
 
 /*  ethers.c
  */