diff --git a/Libraries/LibWeb/CSS/BooleanExpression.h b/Libraries/LibWeb/CSS/BooleanExpression.h
index 85b86ae032d..0ded122c9b5 100644
--- a/Libraries/LibWeb/CSS/BooleanExpression.h
+++ b/Libraries/LibWeb/CSS/BooleanExpression.h
@@ -14,18 +14,42 @@
 namespace Web::CSS {
 
 // Corresponds to Kleene 3-valued logic.
-enum class MatchResult {
+enum class MatchResult : u8 {
     False,
     True,
     Unknown,
 };
 
-inline MatchResult as_match_result(bool value)
+constexpr MatchResult operator&&(MatchResult const a, MatchResult const b)
+{
+    // If either is false, false.
+    if (a == MatchResult::False || b == MatchResult::False)
+        return MatchResult::False;
+    // If both are true, true.
+    if (a == MatchResult::True && b == MatchResult::True)
+        return MatchResult::True;
+    // Otherwise, unknown.
+    return MatchResult::Unknown;
+}
+
+constexpr MatchResult operator||(MatchResult const a, MatchResult const b)
+{
+    // If either is true, true.
+    if (a == MatchResult::True || b == MatchResult::True)
+        return MatchResult::True;
+    // If both are false, false.
+    if (a == MatchResult::False && b == MatchResult::False)
+        return MatchResult::False;
+    // Otherwise, unknown.
+    return MatchResult::Unknown;
+}
+
+constexpr MatchResult as_match_result(bool value)
 {
     return value ? MatchResult::True : MatchResult::False;
 }
 
-inline MatchResult negate(MatchResult value)
+constexpr MatchResult negate(MatchResult value)
 {
     switch (value) {
     case MatchResult::False:
@@ -38,6 +62,19 @@ inline MatchResult negate(MatchResult value)
     VERIFY_NOT_REACHED();
 }
 
+constexpr StringView to_string(MatchResult result)
+{
+    switch (result) {
+    case MatchResult::False:
+        return "false"sv;
+    case MatchResult::True:
+        return "true"sv;
+    case MatchResult::Unknown:
+        return "unknown"sv;
+    }
+    VERIFY_NOT_REACHED();
+}
+
 // The contents of this file implement the `<boolean-expr>` concept.
 // https://drafts.csswg.org/css-values-5/#typedef-boolean-expr
 class BooleanExpression {
diff --git a/Libraries/LibWeb/CSS/MediaQuery.cpp b/Libraries/LibWeb/CSS/MediaQuery.cpp
index 0aed3be483d..7f41aca933b 100644
--- a/Libraries/LibWeb/CSS/MediaQuery.cpp
+++ b/Libraries/LibWeb/CSS/MediaQuery.cpp
@@ -305,8 +305,8 @@ bool MediaQuery::evaluate(HTML::Window const& window)
 
     MatchResult result = matches_media(m_media_type);
 
-    if ((result == MatchResult::True) && m_media_condition)
-        result = m_media_condition->evaluate(&window);
+    if ((result != MatchResult::False) && m_media_condition)
+        result = result && m_media_condition->evaluate(&window);
 
     if (m_negated)
         result = negate(result);