diff --git a/Libraries/LibWeb/CSS/Selector.cpp b/Libraries/LibWeb/CSS/Selector.cpp
index d0dc85681cb..6dd9646c77d 100644
--- a/Libraries/LibWeb/CSS/Selector.cpp
+++ b/Libraries/LibWeb/CSS/Selector.cpp
@@ -348,6 +348,8 @@ String Selector::SimpleSelector::serialize() const
         if (attribute.qualified_name.namespace_type == QualifiedName::NamespaceType::Named) {
             serialize_an_identifier(s, attribute.qualified_name.namespace_);
             s.append('|');
+        } else if (attribute.qualified_name.namespace_type == QualifiedName::NamespaceType::Any) {
+            s.append("*|"sv);
         }
 
         // 3. Append the serialization of the attribute name as an identifier to s.
diff --git a/Tests/LibWeb/Text/expected/wpt-import/css/cssom/selectorSerialize.txt b/Tests/LibWeb/Text/expected/wpt-import/css/cssom/selectorSerialize.txt
index 83c13b75ee2..9d3ab089121 100644
--- a/Tests/LibWeb/Text/expected/wpt-import/css/cssom/selectorSerialize.txt
+++ b/Tests/LibWeb/Text/expected/wpt-import/css/cssom/selectorSerialize.txt
@@ -2,8 +2,8 @@ Harness status: OK
 
 Found 23 tests
 
-19 Pass
-4 Fail
+20 Pass
+3 Fail
 Pass	:nth-child serialization produces canonical form
 Pass	single universal selector shows '*' when serialized.
 Pass	single type (simple) selector in the sequence of simple selectors that is not a universal selector
@@ -19,7 +19,7 @@ Pass	single pseudo (simple) selector ":not" which accepts arguments in the seque
 Pass	escaped character in attribute name
 Fail	escaped character as code point in attribute name
 Pass	escaped character (@) in attribute name
-Fail	escaped character in attribute name with any namespace
+Pass	escaped character in attribute name with any namespace
 Pass	escaped character in attribute prefix
 Pass	escaped character in both attribute prefix and name
 Pass	escaped character (\) in element name
diff --git a/Tests/LibWeb/Text/expected/wpt-import/css/selectors/attribute-selectors/attribute-case/cssom.txt b/Tests/LibWeb/Text/expected/wpt-import/css/selectors/attribute-selectors/attribute-case/cssom.txt
index 62af9a24a95..a8af7c0f074 100644
--- a/Tests/LibWeb/Text/expected/wpt-import/css/selectors/attribute-selectors/attribute-case/cssom.txt
+++ b/Tests/LibWeb/Text/expected/wpt-import/css/selectors/attribute-selectors/attribute-case/cssom.txt
@@ -2,8 +2,7 @@ Harness status: OK
 
 Found 72 tests
 
-60 Pass
-12 Fail
+72 Pass
 Pass	[foo="bar"] /* sanity check */ insertRule
 Pass	[foo="bar"] /* sanity check */ getting CSSRule#cssText
 Pass	[foo="bar"] /* sanity check */ getting CSSStyleRule#selectorText
@@ -37,13 +36,13 @@ Pass	[foo="bar"/**/i] getting CSSRule#cssText in @media
 Pass	[foo="bar"/**/i] getting CSSStyleRule#selectorText in @media
 Pass	[foo="bar"/**/i] setting CSSStyleRule#selectorText in @media
 Pass	[*|foo="bar" i] insertRule
-Fail	[*|foo="bar" i] getting CSSRule#cssText
-Fail	[*|foo="bar" i] getting CSSStyleRule#selectorText
-Fail	[*|foo="bar" i] setting CSSStyleRule#selectorText
+Pass	[*|foo="bar" i] getting CSSRule#cssText
+Pass	[*|foo="bar" i] getting CSSStyleRule#selectorText
+Pass	[*|foo="bar" i] setting CSSStyleRule#selectorText
 Pass	[*|foo="bar" i] insertRule in @media
-Fail	[*|foo="bar" i] getting CSSRule#cssText in @media
-Fail	[*|foo="bar" i] getting CSSStyleRule#selectorText in @media
-Fail	[*|foo="bar" i] setting CSSStyleRule#selectorText in @media
+Pass	[*|foo="bar" i] getting CSSRule#cssText in @media
+Pass	[*|foo="bar" i] getting CSSStyleRule#selectorText in @media
+Pass	[*|foo="bar" i] setting CSSStyleRule#selectorText in @media
 Pass	[foo="bar" s] insertRule
 Pass	[foo="bar" s] getting CSSRule#cssText
 Pass	[foo="bar" s] getting CSSStyleRule#selectorText
@@ -69,10 +68,10 @@ Pass	[foo="bar"/**/s] getting CSSRule#cssText in @media
 Pass	[foo="bar"/**/s] getting CSSStyleRule#selectorText in @media
 Pass	[foo="bar"/**/s] setting CSSStyleRule#selectorText in @media
 Pass	[*|foo="bar" s] insertRule
-Fail	[*|foo="bar" s] getting CSSRule#cssText
-Fail	[*|foo="bar" s] getting CSSStyleRule#selectorText
-Fail	[*|foo="bar" s] setting CSSStyleRule#selectorText
+Pass	[*|foo="bar" s] getting CSSRule#cssText
+Pass	[*|foo="bar" s] getting CSSStyleRule#selectorText
+Pass	[*|foo="bar" s] setting CSSStyleRule#selectorText
 Pass	[*|foo="bar" s] insertRule in @media
-Fail	[*|foo="bar" s] getting CSSRule#cssText in @media
-Fail	[*|foo="bar" s] getting CSSStyleRule#selectorText in @media
-Fail	[*|foo="bar" s] setting CSSStyleRule#selectorText in @media
\ No newline at end of file
+Pass	[*|foo="bar" s] getting CSSRule#cssText in @media
+Pass	[*|foo="bar" s] getting CSSStyleRule#selectorText in @media
+Pass	[*|foo="bar" s] setting CSSStyleRule#selectorText in @media
\ No newline at end of file