diff --git a/Tests/LibWeb/Text/expected/cookie.txt b/Tests/LibWeb/Text/expected/cookie.txt
index f21cf9d5923..44c8a5ab8b2 100644
--- a/Tests/LibWeb/Text/expected/cookie.txt
+++ b/Tests/LibWeb/Text/expected/cookie.txt
@@ -14,9 +14,9 @@ Public suffix: ""
 SameSite=Lax: "cookie=value"
 SameSite=Strict: "cookie=value"
 SameSite=None: ""
-Max-Age (before expiration): "cookie-max-age=value"
-Expires (before expiration): "cookie-expires=value; cookie-max-age=value"
-Max-Age (after expiration): ""
+Max-Age (before expiration): "cookie-max-age1=value; cookie-max-age2=value"
+Expires (before expiration): "cookie-expires=value; cookie-max-age1=value; cookie-max-age2=value"
+Max-Age (after expiration): "cookie-max-age2=value"
 Expires (after expiration): ""
 Max-Age in past: ""
 Expires in past: ""
diff --git a/Tests/LibWeb/Text/input/cookie.html b/Tests/LibWeb/Text/input/cookie.html
index 4087d1d4c99..fc65d5547aa 100644
--- a/Tests/LibWeb/Text/input/cookie.html
+++ b/Tests/LibWeb/Text/input/cookie.html
@@ -113,16 +113,19 @@
     };
 
     const maxAgeTest1 = () => {
-        document.cookie = "cookie-max-age=value; max-age=1";
+        document.cookie = "cookie-max-age1=value; max-age=1";
+        document.cookie = `cookie-max-age2=value; max-age=${"1".repeat(1024)}`;
         printCookies("Max-Age (before expiration)");
     };
 
     const maxAgeTest2 = () => {
         printCookies("Max-Age (after expiration)");
+        deleteCookie("cookie-max-age2");
     };
 
     const maxAgeInPastTest = () => {
-        document.cookie = "cookie=value; max-age=-1";
+        document.cookie = "cookie1=value; max-age=-1";
+        document.cookie = `cookie2=value; max-age=-${"1".repeat(1023)}`;
         printCookies("Max-Age in past");
     };
 
diff --git a/Userland/Libraries/LibWeb/Cookie/ParsedCookie.cpp b/Userland/Libraries/LibWeb/Cookie/ParsedCookie.cpp
index d34fcb605fc..09c28ab0b2f 100644
--- a/Userland/Libraries/LibWeb/Cookie/ParsedCookie.cpp
+++ b/Userland/Libraries/LibWeb/Cookie/ParsedCookie.cpp
@@ -226,14 +226,20 @@ void on_max_age_attribute(ParsedCookie& parsed_cookie, StringView attribute_valu
 
     // 2. If the first character of the attribute-value is neither a DIGIT, nor a "-" character followed by a DIGIT,
     //    ignore the cookie-av.
-    if (!is_ascii_digit(attribute_value[0]) && attribute_value[0] != '-')
+    // 3. If the remainder of attribute-value contains a non-DIGIT character, ignore the cookie-av.
+    auto digits = attribute_value[0] == '-' ? attribute_value.substring_view(1) : attribute_value;
+
+    if (digits.is_empty() || !all_of(digits, is_ascii_digit))
         return;
 
-    // 3. If the remainder of attribute-value contains a non-DIGIT character, ignore the cookie-av.
     // 4. Let delta-seconds be the attribute-value converted to a base 10 integer.
     auto delta_seconds = attribute_value.to_number<i64>();
-    if (!delta_seconds.has_value())
-        return;
+    if (!delta_seconds.has_value()) {
+        // We know the attribute value only contains digits, so if we failed to parse, it is because the result did not
+        // fit in an i64. Set the value to the i64 limits in that case. The positive limit will be further capped below,
+        // and the negative limit will be immediately expired in the cookie jar.
+        delta_seconds = attribute_value[0] == '-' ? NumericLimits<i64>::min() : NumericLimits<i64>::max();
+    }
 
     // 5. Let cookie-age-limit be the maximum age of the cookie (which SHOULD be 400 days or less, see Section 5.5).
     auto cookie_age_limit = maximum_cookie_age();