diff --git a/cmd-resize-window.c b/cmd-resize-window.c
index ad739165..c420451c 100644
--- a/cmd-resize-window.c
+++ b/cmd-resize-window.c
@@ -53,8 +53,7 @@ cmd_resize_window_exec(struct cmd *self, struct cmdq_item *item)
 	struct session		*s = target->s;
 	const char	       	*errstr;
 	char			*cause;
-	u_int			 adjust, sx, sy;
-	int			 xpixel = -1, ypixel = -1;
+	u_int			 adjust, sx, sy, xpixel = 0, ypixel = 0;
 
 	if (args_count(args) == 0)
 		adjust = 1;
diff --git a/format.c b/format.c
index f69330b2..13348803 100644
--- a/format.c
+++ b/format.c
@@ -3813,7 +3813,7 @@ format_build_modifiers(struct format_expand_state *es, const char **s,
 		argc = 0;
 
 		/* Single argument with no wrapper character. */
-		if (!ispunct(cp[1]) || cp[1] == '-') {
+		if (!ispunct((u_char)cp[1]) || cp[1] == '-') {
 			end = format_skip(cp + 1, ":;");
 			if (end == NULL)
 				break;
diff --git a/hyperlinks.c b/hyperlinks.c
index cde500c0..70c2f4e3 100644
--- a/hyperlinks.c
+++ b/hyperlinks.c
@@ -42,7 +42,7 @@
 
 #define MAX_HYPERLINKS 5000
 
-static uint64_t hyperlinks_next_external_id = 1;
+static long long hyperlinks_next_external_id = 1;
 static u_int global_hyperlinks_count;
 
 struct hyperlinks_uri {
diff --git a/input.c b/input.c
index b2d28386..dd22ac75 100644
--- a/input.c
+++ b/input.c
@@ -2842,9 +2842,11 @@ input_reply_clipboard(struct bufferevent *bev, const char *buf, size_t len,
     const char *end)
 {
 	char	*out = NULL;
-	size_t	 outlen = 0;
+	int	 outlen = 0;
 
 	if (buf != NULL && len != 0) {
+		if (len >= ((size_t)INT_MAX * 3 / 4) - 1)
+			return;
 		outlen = 4 * ((len + 2) / 3) + 1;
 		out = xmalloc(outlen);
 		if ((outlen = b64_ntop(buf, len, out, outlen)) == -1) {
diff --git a/notify.c b/notify.c
index 97919487..d42e2b9d 100644
--- a/notify.c
+++ b/notify.c
@@ -193,7 +193,7 @@ notify_add(const char *name, struct cmd_find_state *fs, struct client *c,
 	ne->client = c;
 	ne->session = s;
 	ne->window = w;
-	ne->pane = (wp != NULL ? wp->id : -1);
+	ne->pane = (wp != NULL ? (int)wp->id : -1);
 	ne->pbname = (pbname != NULL ? xstrdup(pbname) : NULL);
 
 	ne->formats = format_create(NULL, NULL, 0, FORMAT_NOJOBS);
@@ -240,7 +240,7 @@ notify_hook(struct cmdq_item *item, const char *name)
 	ne.client = cmdq_get_client(item);
 	ne.session = target->s;
 	ne.window = target->w;
-	ne.pane = (target->wp != NULL ? target->wp->id : -1);
+	ne.pane = (target->wp != NULL ? (int)target->wp->id : -1);
 
 	ne.formats = format_create(NULL, NULL, 0, FORMAT_NOJOBS);
 	format_add(ne.formats, "hook", "%s", name);
diff --git a/tty-keys.c b/tty-keys.c
index 25956c4d..e3000e5a 100644
--- a/tty-keys.c
+++ b/tty-keys.c
@@ -1160,7 +1160,7 @@ tty_keys_clipboard(struct tty *tty, const char *buf, size_t len, size_t *size)
 {
 	struct client		*c = tty->client;
 	struct window_pane	*wp;
-	size_t			 end, terminator, needed;
+	size_t			 end, terminator = 0, needed;
 	char			*copy, *out;
 	int			 outlen;
 	u_int			 i;
diff --git a/tty-term.c b/tty-term.c
index 7dbcfee7..e2242269 100644
--- a/tty-term.c
+++ b/tty-term.c
@@ -718,7 +718,7 @@ tty_term_read_list(const char *name, int fd, char ***caps, u_int *ncaps,
 			s = tmp;
 			break;
 		case TTYCODE_FLAG:
-			n = tigetflag((char *) ent->name);
+			n = tigetflag((char *)ent->name);
 			if (n == -1)
 				continue;
 			if (n)
@@ -726,6 +726,8 @@ tty_term_read_list(const char *name, int fd, char ***caps, u_int *ncaps,
 			else
 				s = "0";
 			break;
+		default:
+			fatalx("unknown capability type");
 		}
 		*caps = xreallocarray(*caps, (*ncaps) + 1, sizeof **caps);
 		xasprintf(&(*caps)[*ncaps], "%s=%s", ent->name, s);