diff --git a/Libraries/LibWeb/HTML/HTMLMarqueeElement.cpp b/Libraries/LibWeb/HTML/HTMLMarqueeElement.cpp
index 435da552192..e3380e45c36 100644
--- a/Libraries/LibWeb/HTML/HTMLMarqueeElement.cpp
+++ b/Libraries/LibWeb/HTML/HTMLMarqueeElement.cpp
@@ -67,7 +67,7 @@ WebIDL::UnsignedLong HTMLMarqueeElement::scroll_amount()
 {
     // The scrollAmount IDL attribute must reflect the scrollamount content attribute. The default value is 6.
     if (auto scroll_amount_string = get_attribute(HTML::AttributeNames::scrollamount); scroll_amount_string.has_value()) {
-        if (auto scroll_amount = parse_non_negative_integer(*scroll_amount_string); scroll_amount.has_value())
+        if (auto scroll_amount = parse_non_negative_integer(*scroll_amount_string); scroll_amount.has_value() && *scroll_amount <= 2147483647)
             return *scroll_amount;
     }
     return 6;
@@ -76,6 +76,8 @@ WebIDL::UnsignedLong HTMLMarqueeElement::scroll_amount()
 // https://html.spec.whatwg.org/multipage/obsolete.html#dom-marquee-scrollamount
 WebIDL::ExceptionOr<void> HTMLMarqueeElement::set_scroll_amount(WebIDL::UnsignedLong value)
 {
+    if (value > 2147483647)
+        value = 6;
     return set_attribute(HTML::AttributeNames::scrollamount, String::number(value));
 }
 
@@ -84,7 +86,7 @@ WebIDL::UnsignedLong HTMLMarqueeElement::scroll_delay()
 {
     // The scrollDelay IDL attribute must reflect the scrolldelay content attribute. The default value is 85.
     if (auto scroll_delay_string = get_attribute(HTML::AttributeNames::scrolldelay); scroll_delay_string.has_value()) {
-        if (auto scroll_delay = parse_non_negative_integer(*scroll_delay_string); scroll_delay.has_value())
+        if (auto scroll_delay = parse_non_negative_integer(*scroll_delay_string); scroll_delay.has_value() && *scroll_delay <= 2147483647)
             return *scroll_delay;
     }
     return 85;
@@ -93,6 +95,8 @@ WebIDL::UnsignedLong HTMLMarqueeElement::scroll_delay()
 // https://html.spec.whatwg.org/multipage/obsolete.html#dom-marquee-scrolldelay
 WebIDL::ExceptionOr<void> HTMLMarqueeElement::set_scroll_delay(WebIDL::UnsignedLong value)
 {
+    if (value > 2147483647)
+        value = 85;
     return set_attribute(HTML::AttributeNames::scrolldelay, String::number(value));
 }
 
diff --git a/Tests/LibWeb/Text/expected/HTML/unsigned-long-reflection.txt b/Tests/LibWeb/Text/expected/HTML/unsigned-long-reflection.txt
index 4d99f6bfd21..565a060efba 100644
--- a/Tests/LibWeb/Text/expected/HTML/unsigned-long-reflection.txt
+++ b/Tests/LibWeb/Text/expected/HTML/unsigned-long-reflection.txt
@@ -14,3 +14,35 @@ img.getAttribute("hspace") after img.setAttribute("hspace", "4294967295"): 42949
 img.hspace after img.setAttribute("hspace", "4294967295"): 0
 img.getAttribute("hspace") after img.hspace = 4294967295: 0
 img.hspace after img.hspace = 4294967295: 0
+marquee.getAttribute("scrollamount") after marquee.setAttribute("scrollAmount", "1"): 1
+marquee.scrollAmount after marquee.setAttribute("scrollamount", "1"): 1
+marquee.getAttribute("scrollamount") after marquee.scrollAmount = 1: 1
+marquee.scrollAmount after marquee.scrollAmount = 1: 1
+marquee.getAttribute("scrollamount") after marquee.setAttribute("scrollAmount", "2147483647"): 2147483647
+marquee.scrollAmount after marquee.setAttribute("scrollamount", "2147483647"): 2147483647
+marquee.getAttribute("scrollamount") after marquee.scrollAmount = 2147483647: 2147483647
+marquee.scrollAmount after marquee.scrollAmount = 2147483647: 2147483647
+marquee.getAttribute("scrollamount") after marquee.setAttribute("scrollAmount", "2147483648"): 2147483648
+marquee.scrollAmount after marquee.setAttribute("scrollamount", "2147483648"): 6
+marquee.getAttribute("scrollamount") after marquee.scrollAmount = 2147483648: 6
+marquee.scrollAmount after marquee.scrollAmount = 2147483648: 6
+marquee.getAttribute("scrollamount") after marquee.setAttribute("scrollAmount", "4294967295"): 4294967295
+marquee.scrollAmount after marquee.setAttribute("scrollamount", "4294967295"): 6
+marquee.getAttribute("scrollamount") after marquee.scrollAmount = 4294967295: 6
+marquee.scrollAmount after marquee.scrollAmount = 4294967295: 6
+marquee.getAttribute("scrolldelay") after marquee.setAttribute("scrollDelay", "1"): 1
+marquee.scrollDelay after marquee.setAttribute("scrolldelay", "1"): 1
+marquee.getAttribute("scrolldelay") after marquee.scrollDelay = 1: 1
+marquee.scrollDelay after marquee.scrollDelay = 1: 1
+marquee.getAttribute("scrolldelay") after marquee.setAttribute("scrollDelay", "2147483647"): 2147483647
+marquee.scrollDelay after marquee.setAttribute("scrolldelay", "2147483647"): 2147483647
+marquee.getAttribute("scrolldelay") after marquee.scrollDelay = 2147483647: 2147483647
+marquee.scrollDelay after marquee.scrollDelay = 2147483647: 2147483647
+marquee.getAttribute("scrolldelay") after marquee.setAttribute("scrollDelay", "2147483648"): 2147483648
+marquee.scrollDelay after marquee.setAttribute("scrolldelay", "2147483648"): 85
+marquee.getAttribute("scrolldelay") after marquee.scrollDelay = 2147483648: 85
+marquee.scrollDelay after marquee.scrollDelay = 2147483648: 85
+marquee.getAttribute("scrolldelay") after marquee.setAttribute("scrollDelay", "4294967295"): 4294967295
+marquee.scrollDelay after marquee.setAttribute("scrolldelay", "4294967295"): 85
+marquee.getAttribute("scrolldelay") after marquee.scrollDelay = 4294967295: 85
+marquee.scrollDelay after marquee.scrollDelay = 4294967295: 85
diff --git a/Tests/LibWeb/Text/input/HTML/unsigned-long-reflection.html b/Tests/LibWeb/Text/input/HTML/unsigned-long-reflection.html
index b012b14c14b..d951a6754d1 100644
--- a/Tests/LibWeb/Text/input/HTML/unsigned-long-reflection.html
+++ b/Tests/LibWeb/Text/input/HTML/unsigned-long-reflection.html
@@ -23,5 +23,7 @@
         }
 
         testProperty("img", "hspace", (img) => img.hspace, (img, value) => img.hspace = value);
+        testProperty("marquee", "scrollAmount", (marquee) => marquee.scrollAmount, (marquee, value) => marquee.scrollAmount = value);
+        testProperty("marquee", "scrollDelay", (marquee) => marquee.scrollDelay, (marquee, value) => marquee.scrollDelay = value);
     });
 </script>