diff --git a/cmdline.c b/cmdline.c
index aa8cfda4..1ae74406 100644
--- a/cmdline.c
+++ b/cmdline.c
@@ -152,6 +152,18 @@ bool cmdline_seat_verbose(Seat *seat) { return cmdline_verbose(); }
 bool cmdline_lp_verbose(LogPolicy *lp) { return cmdline_verbose(); }
 bool cmdline_loaded_session(void) { return loaded_session; }
 
+static void set_protocol(Conf *conf, int protocol)
+{
+    settings_set_default_protocol(protocol);
+    conf_set_int(conf, CONF_protocol, protocol);
+}
+
+static void set_port(Conf *conf, int port)
+{
+    settings_set_default_port(port);
+    conf_set_int(conf, CONF_port, port);
+}
+
 int cmdline_process_param(const char *p, char *value,
                           int need_save, Conf *conf)
 {
@@ -269,9 +281,7 @@ int cmdline_process_param(const char *p, char *value,
                             backend_vt_from_name(prefix);
 
                         if (vt) {
-                            default_protocol = vt->protocol;
-                            conf_set_int(conf, CONF_protocol,
-                                         default_protocol);
+                            set_protocol(conf, vt->protocol);
                             port_override = vt->default_port;
                         } else {
                             cmdline_error("unrecognised protocol prefix '%s'",
@@ -399,46 +409,38 @@ int cmdline_process_param(const char *p, char *value,
         RETURN(1);
         UNAVAILABLE_IN(TOOLTYPE_FILETRANSFER | TOOLTYPE_NONNETWORK);
         SAVEABLE(0);
-        default_protocol = PROT_SSH;
-        default_port = 22;
-        conf_set_int(conf, CONF_protocol, default_protocol);
-        conf_set_int(conf, CONF_port, default_port);
+        set_protocol(conf, PROT_SSH);
+        set_port(conf, 22);
         return 1;
     }
     if (!strcmp(p, "-telnet")) {
         RETURN(1);
         UNAVAILABLE_IN(TOOLTYPE_FILETRANSFER | TOOLTYPE_NONNETWORK);
         SAVEABLE(0);
-        default_protocol = PROT_TELNET;
-        default_port = 23;
-        conf_set_int(conf, CONF_protocol, default_protocol);
-        conf_set_int(conf, CONF_port, default_port);
+        set_protocol(conf, PROT_TELNET);
+        set_port(conf, 23);
         return 1;
     }
     if (!strcmp(p, "-rlogin")) {
         RETURN(1);
         UNAVAILABLE_IN(TOOLTYPE_FILETRANSFER | TOOLTYPE_NONNETWORK);
         SAVEABLE(0);
-        default_protocol = PROT_RLOGIN;
-        default_port = 513;
-        conf_set_int(conf, CONF_protocol, default_protocol);
-        conf_set_int(conf, CONF_port, default_port);
+        set_protocol(conf, PROT_RLOGIN);
+        set_port(conf, 513);
         return 1;
     }
     if (!strcmp(p, "-raw")) {
         RETURN(1);
         UNAVAILABLE_IN(TOOLTYPE_FILETRANSFER | TOOLTYPE_NONNETWORK);
         SAVEABLE(0);
-        default_protocol = PROT_RAW;
-        conf_set_int(conf, CONF_protocol, default_protocol);
+        set_protocol(conf, PROT_RAW);
     }
     if (!strcmp(p, "-serial")) {
         RETURN(1);
         /* Serial is not NONNETWORK in an odd sense of the word */
         UNAVAILABLE_IN(TOOLTYPE_FILETRANSFER | TOOLTYPE_NONNETWORK);
         SAVEABLE(0);
-        default_protocol = PROT_SERIAL;
-        conf_set_int(conf, CONF_protocol, default_protocol);
+        set_protocol(conf, PROT_SERIAL);
         /* The host parameter will already be loaded into CONF_host,
          * so copy it across */
         conf_set_str(conf, CONF_serline, conf_get_str(conf, CONF_host));
diff --git a/pscp.c b/pscp.c
index dc9ebb8d..c25226b9 100644
--- a/pscp.c
+++ b/pscp.c
@@ -2229,7 +2229,7 @@ int psftp_main(int argc, char *argv[])
     int i;
     bool sanitise_stderr = true;
 
-    default_protocol = PROT_TELNET;
+    settings_set_default_protocol(PROT_TELNET);
 
     sk_init();
 
diff --git a/putty.h b/putty.h
index b1d0d30b..0fac7592 100644
--- a/putty.h
+++ b/putty.h
@@ -4,19 +4,6 @@
 #include <stddef.h>                    /* for wchar_t */
 #include <limits.h>                    /* for INT_MAX */
 
-/*
- * Global variables. Most modules declare these `extern', but
- * window.c will do `#define PUTTY_DO_GLOBALS' before including this
- * module, and so will get them properly defined.
- */
-#ifndef GLOBAL
-#ifdef PUTTY_DO_GLOBALS
-#define GLOBAL
-#else
-#define GLOBAL extern
-#endif
-#endif
-
 #include "defs.h"
 #include "puttyps.h"
 #include "network.h"
@@ -578,14 +565,6 @@ extern const int be_default_protocol;
  */
 extern const char *const appname;
 
-/*
- * Likewise, these two variables are set up when the application
- * initialises, and inform all default-settings accesses after
- * that.
- */
-GLOBAL int default_protocol;
-GLOBAL int default_port;
-
 /*
  * Mechanism for getting text strings such as usernames and passwords
  * from the front-end.
@@ -1562,6 +1541,8 @@ void load_open_settings(settings_r *sesskey, Conf *conf);
 void get_sesslist(struct sesslist *, bool allocate);
 bool do_defaults(const char *, Conf *);
 void registry_cleanup(void);
+void settings_set_default_protocol(int);
+void settings_set_default_port(int);
 
 /*
  * Functions used by settings.c to provide platform-specific
diff --git a/settings.c b/settings.c
index 7bf7e4d2..5eaaa5f1 100644
--- a/settings.c
+++ b/settings.c
@@ -69,6 +69,10 @@ const char *const ttymodes[] = {
     "CS7",      "CS8",      "PARENB",   "PARODD",   NULL
 };
 
+static int default_protocol, default_port;
+void settings_set_default_protocol(int newval) { default_protocol = newval; }
+void settings_set_default_port(int newval) { default_port = newval; }
+
 /*
  * Convenience functions to access the backends[] array
  * (which is only present in tools that manage settings).
diff --git a/unix/uxplink.c b/unix/uxplink.c
index 0d555a70..f75b04ce 100644
--- a/unix/uxplink.c
+++ b/unix/uxplink.c
@@ -598,8 +598,8 @@ int main(int argc, char **argv)
      * Initialise port and protocol to sensible defaults. (These
      * will be overridden by more or less anything.)
      */
-    default_protocol = PROT_SSH;
-    default_port = 22;
+    settings_set_default_protocol(PROT_SSH);
+    settings_set_default_port(22);
 
     bufchain_init(&stdout_data);
     bufchain_init(&stderr_data);
@@ -615,8 +615,8 @@ int main(int argc, char **argv)
      */
     conf = conf_new();
     do_defaults(NULL, conf);
-    default_protocol = conf_get_int(conf, CONF_protocol);
-    default_port = conf_get_int(conf, CONF_port);
+    settings_set_default_protocol(conf_get_int(conf, CONF_protocol));
+    settings_set_default_port(conf_get_int(conf, CONF_port));
     errors = false;
     {
         /*
@@ -626,10 +626,10 @@ int main(int argc, char **argv)
         if (p) {
             const struct BackendVtable *vt = backend_vt_from_name(p);
             if (vt) {
-                default_protocol = vt->protocol;
-                default_port = vt->default_port;
-                conf_set_int(conf, CONF_protocol, default_protocol);
-                conf_set_int(conf, CONF_port, default_port);
+                settings_set_default_protocol(vt->protocol);
+                settings_set_default_port(vt->default_port);
+                conf_set_int(conf, CONF_protocol, vt->protocol);
+                conf_set_int(conf, CONF_port, vt->default_port);
             }
         }
     }
diff --git a/unix/uxpterm.c b/unix/uxpterm.c
index ff8ff6cd..9d768a4c 100644
--- a/unix/uxpterm.c
+++ b/unix/uxpterm.c
@@ -48,7 +48,7 @@ char *make_default_wintitle(char *hostname)
 
 void setup(bool single)
 {
-    default_protocol = -1;
+    settings_set_default_protocol(-1);
 
     if (single)
         pty_pre_init();
diff --git a/unix/uxputty.c b/unix/uxputty.c
index 3611712b..1b44c2fd 100644
--- a/unix/uxputty.c
+++ b/unix/uxputty.c
@@ -85,13 +85,13 @@ const unsigned cmdline_tooltype =
 void setup(bool single)
 {
     sk_init();
-    default_protocol = be_default_protocol;
+    settings_set_default_protocol(be_default_protocol);
     /* Find the appropriate default port. */
     {
         const struct BackendVtable *vt =
-            backend_vt_from_proto(default_protocol);
-        default_port = 0; /* illegal */
+            backend_vt_from_proto(be_default_protocol);
+        settings_set_default_port(0); /* illegal */
         if (vt)
-            default_port = vt->default_port;
+            settings_set_default_port(vt->default_port);
     }
 }
diff --git a/windows/window.c b/windows/window.c
index b223cb9a..3125c55a 100644
--- a/windows/window.c
+++ b/windows/window.c
@@ -532,14 +532,14 @@ int WINAPI WinMain(HINSTANCE inst, HINSTANCE prev, LPSTR cmdline, int show)
         char *p;
         bool special_launchable_argument = false;
 
-        default_protocol = be_default_protocol;
+        settings_set_default_protocol(be_default_protocol);
         /* Find the appropriate default port. */
         {
             const struct BackendVtable *vt =
-                backend_vt_from_proto(default_protocol);
-            default_port = 0; /* illegal */
+                backend_vt_from_proto(be_default_protocol);
+            settings_set_default_port(0); /* illegal */
             if (vt)
-                default_port = vt->default_port;
+                settings_set_default_port(vt->default_port);
         }
         conf_set_int(conf, CONF_logtype, LGTYP_NONE);
 
diff --git a/windows/winplink.c b/windows/winplink.c
index d9b2020d..dd0bcc34 100644
--- a/windows/winplink.c
+++ b/windows/winplink.c
@@ -252,16 +252,16 @@ int main(int argc, char **argv)
      * Initialise port and protocol to sensible defaults. (These
      * will be overridden by more or less anything.)
      */
-    default_protocol = PROT_SSH;
-    default_port = 22;
+    settings_set_default_protocol(PROT_SSH);
+    settings_set_default_port(22);
 
     /*
      * Process the command line.
      */
     conf = conf_new();
     do_defaults(NULL, conf);
-    default_protocol = conf_get_int(conf, CONF_protocol);
-    default_port = conf_get_int(conf, CONF_port);
+    settings_set_default_protocol(conf_get_int(conf, CONF_protocol));
+    settings_set_default_port(conf_get_int(conf, CONF_port));
     errors = false;
     {
         /*
@@ -271,10 +271,10 @@ int main(int argc, char **argv)
         if (p) {
             const struct BackendVtable *vt = backend_vt_from_name(p);
             if (vt) {
-                default_protocol = vt->protocol;
-                default_port = vt->default_port;
-                conf_set_int(conf, CONF_protocol, default_protocol);
-                conf_set_int(conf, CONF_port, default_port);
+                settings_set_default_protocol(vt->protocol);
+                settings_set_default_port(vt->default_port);
+                conf_set_int(conf, CONF_protocol, vt->protocol);
+                conf_set_int(conf, CONF_port, vt->default_port);
             }
         }
     }