diff --git a/Libraries/LibWeb/CSS/StyleSheetIdentifier.cpp b/Libraries/LibWeb/CSS/StyleSheetIdentifier.cpp
index d96f3378d0a..c821886def4 100644
--- a/Libraries/LibWeb/CSS/StyleSheetIdentifier.cpp
+++ b/Libraries/LibWeb/CSS/StyleSheetIdentifier.cpp
@@ -52,6 +52,7 @@ ErrorOr<void> encode(Encoder& encoder, Web::CSS::StyleSheetIdentifier const& sty
     TRY(encoder.encode(style_sheet_source.type));
     TRY(encoder.encode(style_sheet_source.dom_element_unique_id.map([](auto value) { return value.value(); })));
     TRY(encoder.encode(style_sheet_source.url));
+    TRY(encoder.encode(style_sheet_source.rule_count));
 
     return {};
 }
@@ -62,11 +63,13 @@ ErrorOr<Web::CSS::StyleSheetIdentifier> decode(Decoder& decoder)
     auto type = TRY(decoder.decode<Web::CSS::StyleSheetIdentifier::Type>());
     auto dom_element_unique_id = TRY(decoder.decode<Optional<Web::UniqueNodeID::Type>>());
     auto url = TRY(decoder.decode<Optional<String>>());
+    auto rule_count = TRY(decoder.decode<size_t>());
 
     return Web::CSS::StyleSheetIdentifier {
         .type = type,
         .dom_element_unique_id = dom_element_unique_id.map([](auto value) -> Web::UniqueNodeID { return value; }),
         .url = move(url),
+        .rule_count = rule_count,
     };
 }
 
diff --git a/Libraries/LibWeb/CSS/StyleSheetIdentifier.h b/Libraries/LibWeb/CSS/StyleSheetIdentifier.h
index 567239887fe..7c2a8a780dd 100644
--- a/Libraries/LibWeb/CSS/StyleSheetIdentifier.h
+++ b/Libraries/LibWeb/CSS/StyleSheetIdentifier.h
@@ -19,9 +19,12 @@ struct StyleSheetIdentifier {
         ImportRule,
         UserAgent,
         UserStyle,
-    } type;
+    };
+
+    Type type;
     Optional<UniqueNodeID> dom_element_unique_id {};
     Optional<String> url {};
+    size_t rule_count { 0 };
 };
 
 StringView style_sheet_identifier_type_to_string(StyleSheetIdentifier::Type);
diff --git a/Services/WebContent/PageClient.cpp b/Services/WebContent/PageClient.cpp
index 2e917bae179..3513357160b 100644
--- a/Services/WebContent/PageClient.cpp
+++ b/Services/WebContent/PageClient.cpp
@@ -896,6 +896,7 @@ static void gather_style_sheets(Vector<Web::CSS::StyleSheetIdentifier>& results,
         if (auto location = sheet.location(); location.has_value())
             identifier.url = location.release_value();
 
+        identifier.rule_count = sheet.rules().length();
         results.append(move(identifier));
     }
 
@@ -904,8 +905,10 @@ static void gather_style_sheets(Vector<Web::CSS::StyleSheetIdentifier>& results,
             gather_style_sheets(results, *import_rule->loaded_style_sheet());
         } else {
             // We can gather this anyway, and hope it loads later
-            results.append({ .type = Web::CSS::StyleSheetIdentifier::Type::ImportRule,
-                .url = import_rule->url().to_string() });
+            results.append({
+                .type = Web::CSS::StyleSheetIdentifier::Type::ImportRule,
+                .url = import_rule->url().to_string(),
+            });
         }
     }
 }