diff --git a/cmdline.c b/cmdline.c
index fae28e58..d5364ff7 100644
--- a/cmdline.c
+++ b/cmdline.c
@@ -109,18 +109,6 @@ int cmdline_get_passwd_input(prompts_t *p)
     return 1;
 }
 
-/*
- * Here we have a flags word which describes the capabilities of
- * the particular tool on whose behalf we're running. We will
- * refuse certain command-line options if a particular tool
- * inherently can't do anything sensible. For example, the file
- * transfer tools (psftp, pscp) can't do a great deal with protocol
- * selections (ever tried running scp over telnet?) or with port
- * forwarding (even if it wasn't a hideously bad idea, they don't
- * have the select/poll infrastructure to make them work).
- */
-int cmdline_tooltype = 0;
-
 static bool cmdline_check_unavailable(int flag, const char *p)
 {
     if (cmdline_tooltype & flag) {
diff --git a/nocmdline.c b/nocmdline.c
index 05a79baf..e4c6d08f 100644
--- a/nocmdline.c
+++ b/nocmdline.c
@@ -35,8 +35,3 @@ int cmdline_process_param(const char *p, char *value,
 {
     unreachable("cmdline_process_param should never be called");
 }
-
-/*
- * This variable will be referred to, so it has to exist. It's ignored.
- */
-int cmdline_tooltype = 0;
diff --git a/pscp.c b/pscp.c
index a8e276c4..240ffff0 100644
--- a/pscp.c
+++ b/pscp.c
@@ -2218,6 +2218,8 @@ const bool share_can_be_upstream = false;
 static stdio_sink stderr_ss;
 static StripCtrlChars *stderr_scc;
 
+const unsigned cmdline_tooltype = TOOLTYPE_FILETRANSFER;
+
 /*
  * Main program. (Called `psftp_main' because it gets called from
  * *sftp.c; bit silly, I know, but it had to be called _something_.)
@@ -2229,7 +2231,6 @@ int psftp_main(int argc, char *argv[])
 
     default_protocol = PROT_TELNET;
 
-    cmdline_tooltype = TOOLTYPE_FILETRANSFER;
     sk_init();
 
     /* Load Default Settings before doing anything else. */
diff --git a/psftp.c b/psftp.c
index 3b4b6eb3..a47599e3 100644
--- a/psftp.c
+++ b/psftp.c
@@ -2750,6 +2750,8 @@ const bool share_can_be_upstream = false;
 static stdio_sink stderr_ss;
 static StripCtrlChars *stderr_scc;
 
+const unsigned cmdline_tooltype = TOOLTYPE_FILETRANSFER;
+
 /*
  * Main program. Parse arguments etc.
  */
@@ -2763,7 +2765,6 @@ int psftp_main(int argc, char *argv[])
     bool sanitise_stderr = true;
     char *batchfile = NULL;
 
-    cmdline_tooltype = TOOLTYPE_FILETRANSFER;
     sk_init();
 
     userhost = user = NULL;
diff --git a/putty.h b/putty.h
index 572d8ab2..041d81bc 100644
--- a/putty.h
+++ b/putty.h
@@ -1962,15 +1962,34 @@ void cmdline_cleanup(void);
 int cmdline_get_passwd_input(prompts_t *p);
 bool cmdline_host_ok(Conf *);
 bool cmdline_verbose(void);
-#define TOOLTYPE_FILETRANSFER 1
-#define TOOLTYPE_NONNETWORK 2
-#define TOOLTYPE_HOST_ARG 4
-#define TOOLTYPE_HOST_ARG_CAN_BE_SESSION 8
-#define TOOLTYPE_HOST_ARG_PROTOCOL_PREFIX 16
-#define TOOLTYPE_HOST_ARG_FROM_LAUNCHABLE_LOAD 32
-#define TOOLTYPE_PORT_ARG 64
-#define TOOLTYPE_NO_VERBOSE_OPTION 128
-extern int cmdline_tooltype;
+
+/*
+ * Here we have a flags word provided by each tool, which describes
+ * the capabilities of that tool that cmdline.c needs to know about.
+ * It will refuse certain command-line options if a particular tool
+ * inherently can't do anything sensible. For example, the file
+ * transfer tools (psftp, pscp) can't do a great deal with protocol
+ * selections (ever tried running scp over telnet?) or with port
+ * forwarding (even if it wasn't a hideously bad idea, they don't have
+ * the select/poll infrastructure to make them work).
+ */
+extern const unsigned cmdline_tooltype;
+
+/* Bit flags for the above */
+#define TOOLTYPE_LIST(X)                        \
+    X(TOOLTYPE_FILETRANSFER)                    \
+    X(TOOLTYPE_NONNETWORK)                      \
+    X(TOOLTYPE_HOST_ARG)                        \
+    X(TOOLTYPE_HOST_ARG_CAN_BE_SESSION)         \
+    X(TOOLTYPE_HOST_ARG_PROTOCOL_PREFIX)        \
+    X(TOOLTYPE_HOST_ARG_FROM_LAUNCHABLE_LOAD)   \
+    X(TOOLTYPE_PORT_ARG)                        \
+    X(TOOLTYPE_NO_VERBOSE_OPTION)               \
+    /* end of list */
+#define BITFLAG_INDEX(val) val ## _bitflag_index,
+enum { TOOLTYPE_LIST(BITFLAG_INDEX) };
+#define BITFLAG_DEF(val) val = 1U << (val ## _bitflag_index),
+enum { TOOLTYPE_LIST(BITFLAG_DEF) };
 
 void cmdline_error(const char *, ...) PRINTF_LIKE(1, 2);
 
diff --git a/unix/uxplink.c b/unix/uxplink.c
index af08bcbd..c5b3eb96 100644
--- a/unix/uxplink.c
+++ b/unix/uxplink.c
@@ -570,6 +570,12 @@ const bool share_can_be_upstream = true;
 
 const bool buildinfo_gtk_relevant = false;
 
+const unsigned cmdline_tooltype =
+    TOOLTYPE_HOST_ARG |
+    TOOLTYPE_HOST_ARG_CAN_BE_SESSION |
+    TOOLTYPE_HOST_ARG_PROTOCOL_PREFIX |
+    TOOLTYPE_HOST_ARG_FROM_LAUNCHABLE_LOAD;
+
 int main(int argc, char **argv)
 {
     bool sending;
@@ -603,12 +609,6 @@ int main(int argc, char **argv)
     stderr_bs = BinarySink_UPCAST(&stderr_bcs);
     outgoingeof = EOF_NO;
 
-    cmdline_tooltype |=
-        (TOOLTYPE_HOST_ARG |
-         TOOLTYPE_HOST_ARG_CAN_BE_SESSION |
-         TOOLTYPE_HOST_ARG_PROTOCOL_PREFIX |
-         TOOLTYPE_HOST_ARG_FROM_LAUNCHABLE_LOAD);
-
     stderr_tty_init();
     /*
      * Process the command line.
diff --git a/unix/uxpterm.c b/unix/uxpterm.c
index 054d56e5..ff8ff6cd 100644
--- a/unix/uxpterm.c
+++ b/unix/uxpterm.c
@@ -14,6 +14,8 @@ const bool dup_check_launchable = false; /* no need to check host name
                                           * in conf */
 const bool use_pty_argv = true;
 
+const unsigned cmdline_tooltype = TOOLTYPE_NONNETWORK;
+
 /* gtkwin.c will call this, and in pterm it's not needed */
 void noise_ultralight(NoiseSourceId id, unsigned long data) { }
 
@@ -46,7 +48,6 @@ char *make_default_wintitle(char *hostname)
 
 void setup(bool single)
 {
-    cmdline_tooltype = TOOLTYPE_NONNETWORK;
     default_protocol = -1;
 
     if (single)
diff --git a/unix/uxputty.c b/unix/uxputty.c
index 9299bd80..3611712b 100644
--- a/unix/uxputty.c
+++ b/unix/uxputty.c
@@ -77,11 +77,14 @@ char *platform_get_x_display(void) {
 const bool share_can_be_downstream = true;
 const bool share_can_be_upstream = true;
 
+const unsigned cmdline_tooltype =
+    TOOLTYPE_HOST_ARG |
+    TOOLTYPE_PORT_ARG |
+    TOOLTYPE_NO_VERBOSE_OPTION;
+
 void setup(bool single)
 {
     sk_init();
-    cmdline_tooltype |= TOOLTYPE_HOST_ARG | TOOLTYPE_PORT_ARG |
-        TOOLTYPE_NO_VERBOSE_OPTION;
     default_protocol = be_default_protocol;
     /* Find the appropriate default port. */
     {
diff --git a/windows/window.c b/windows/window.c
index 7a82b4ce..b223cb9a 100644
--- a/windows/window.c
+++ b/windows/window.c
@@ -467,6 +467,11 @@ static void close_session(void *ignored_context)
 
 extern LogPolicy win_gui_logpolicy[1]; /* defined in windlg.c */
 
+const unsigned cmdline_tooltype =
+    TOOLTYPE_HOST_ARG |
+    TOOLTYPE_PORT_ARG |
+    TOOLTYPE_NO_VERBOSE_OPTION;
+
 int WINAPI WinMain(HINSTANCE inst, HINSTANCE prev, LPSTR cmdline, int show)
 {
     MSG msg;
@@ -477,8 +482,6 @@ int WINAPI WinMain(HINSTANCE inst, HINSTANCE prev, LPSTR cmdline, int show)
 
     hinst = inst;
     hwnd = NULL;
-    cmdline_tooltype |= TOOLTYPE_HOST_ARG | TOOLTYPE_PORT_ARG |
-        TOOLTYPE_NO_VERBOSE_OPTION;
 
     sk_init();
 
diff --git a/windows/winplink.c b/windows/winplink.c
index f708a72e..cac38ddb 100644
--- a/windows/winplink.c
+++ b/windows/winplink.c
@@ -225,6 +225,12 @@ void stdouterr_sent(struct handle *h, size_t new_backlog, int err)
 const bool share_can_be_downstream = true;
 const bool share_can_be_upstream = true;
 
+const unsigned cmdline_tooltype =
+    TOOLTYPE_HOST_ARG |
+    TOOLTYPE_HOST_ARG_CAN_BE_SESSION |
+    TOOLTYPE_HOST_ARG_PROTOCOL_PREFIX |
+    TOOLTYPE_HOST_ARG_FROM_LAUNCHABLE_LOAD;
+
 int main(int argc, char **argv)
 {
     bool sending;
@@ -249,12 +255,6 @@ int main(int argc, char **argv)
     default_protocol = PROT_SSH;
     default_port = 22;
 
-    cmdline_tooltype |=
-        (TOOLTYPE_HOST_ARG |
-         TOOLTYPE_HOST_ARG_CAN_BE_SESSION |
-         TOOLTYPE_HOST_ARG_PROTOCOL_PREFIX |
-         TOOLTYPE_HOST_ARG_FROM_LAUNCHABLE_LOAD);
-
     /*
      * Process the command line.
      */