diff --git a/lib/libpcap/scanner.l b/lib/libpcap/scanner.l
index 86a1936b908..0dcd6cc9056 100644
--- a/lib/libpcap/scanner.l
+++ b/lib/libpcap/scanner.l
@@ -1,5 +1,5 @@
 %{
-/*	$OpenBSD: scanner.l,v 1.32 2024/08/29 07:33:50 anton Exp $	*/
+/*	$OpenBSD: scanner.l,v 1.33 2024/09/24 14:20:31 sthen Exp $	*/
 
 /*
  * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997
@@ -26,7 +26,6 @@
 #include <sys/time.h>
 
 #include <ctype.h>
-#include <limits.h>
 #include <string.h>
 #include <unistd.h>
 #include <vis.h>
@@ -48,6 +47,7 @@
 #include "grammar.h"
 
 static int stoi(char *);
+static inline int xdtoi(int);
 
 #ifdef FLEX_SCANNER
 #define YY_NO_UNPUT
@@ -333,23 +333,41 @@ yywrap(void)
 	return 1;
 }
 
+/* Hex digit to integer. */
+static inline int
+xdtoi(int c)
+{
+	if (isdigit(c))
+		return c - '0';
+	else if (islower(c))
+		return c - 'a' + 10;
+	else
+		return c - 'A' + 10;
+}
+
 /*
- * Convert string to integer supporting also octal and hex notations.
+ * Convert string to integer.  Just like atoi(), but checks for
+ * preceding 0x or 0 and uses hex or octal instead of decimal.
  */
 static int
 stoi(char *s)
 {
-	long lval;
-	char *ep;
+	int base = 10;
+	int n = 0;
 
-	errno = 0;
-	lval = strtol(s, &ep, 0);
-	if (*s == '\0' || *ep != '\0')
-		bpf_error("invalid number %s", s);
-	if ((errno == ERANGE && (lval == LONG_MAX || lval == LONG_MIN)) ||
-	    (lval > INT_MAX || lval < INT_MIN))
-		bpf_error("out of range: %s", s);
+	if (*s == '0') {
+		if (s[1] == 'x' || s[1] == 'X') {
+			s += 2;
+			base = 16;
+		}
+		else {
+			base = 8;
+			s += 1;
+		}
+	}
+	while (*s)
+		n = n * base + xdtoi(*s++);
 
-	return lval;
+	return n;
 }