diff --git a/Libraries/LibWeb/CSS/CSSImportRule.cpp b/Libraries/LibWeb/CSS/CSSImportRule.cpp
index 61b2f541a1a..def42517e11 100644
--- a/Libraries/LibWeb/CSS/CSSImportRule.cpp
+++ b/Libraries/LibWeb/CSS/CSSImportRule.cpp
@@ -53,6 +53,12 @@ void CSSImportRule::visit_edges(Cell::Visitor& visitor)
 void CSSImportRule::set_parent_style_sheet(CSSStyleSheet* parent_style_sheet)
 {
     Base::set_parent_style_sheet(parent_style_sheet);
+
+    if (m_style_sheet && parent_style_sheet) {
+        for (auto owning_document_or_shadow_root : parent_style_sheet->owning_documents_or_shadow_roots())
+            m_style_sheet->add_owning_document_or_shadow_root(*owning_document_or_shadow_root);
+    }
+
     // Crude detection of whether we're already fetching.
     if (m_style_sheet || m_document_load_event_delayer.has_value())
         return;
@@ -174,9 +180,15 @@ void CSSImportRule::set_style_sheet(GC::Ref<CSSStyleSheet> style_sheet)
 {
     m_style_sheet = style_sheet;
     m_style_sheet->set_owner_css_rule(this);
-    m_document->style_computer().invalidate_rule_cache();
+
     m_document->style_computer().load_fonts_from_sheet(*m_style_sheet);
-    m_document->invalidate_style(DOM::StyleInvalidationReason::CSSImportRule);
+
+    if (m_parent_style_sheet) {
+        for (auto owning_document_or_shadow_root : m_parent_style_sheet->owning_documents_or_shadow_roots())
+            m_style_sheet->add_owning_document_or_shadow_root(*owning_document_or_shadow_root);
+    }
+
+    m_style_sheet->invalidate_owners(DOM::StyleInvalidationReason::CSSImportRule);
 }
 
 // https://drafts.csswg.org/cssom/#dom-cssimportrule-media
diff --git a/Libraries/LibWeb/CSS/CSSStyleSheet.cpp b/Libraries/LibWeb/CSS/CSSStyleSheet.cpp
index 577565ced71..8f40d6e6453 100644
--- a/Libraries/LibWeb/CSS/CSSStyleSheet.cpp
+++ b/Libraries/LibWeb/CSS/CSSStyleSheet.cpp
@@ -321,11 +321,21 @@ void CSSStyleSheet::add_owning_document_or_shadow_root(DOM::Node& document_or_sh
 {
     VERIFY(document_or_shadow_root.is_document() || document_or_shadow_root.is_shadow_root());
     m_owning_documents_or_shadow_roots.set(document_or_shadow_root);
+
+    for (auto const& import_rule : m_import_rules) {
+        if (import_rule->loaded_style_sheet())
+            import_rule->loaded_style_sheet()->add_owning_document_or_shadow_root(document_or_shadow_root);
+    }
 }
 
 void CSSStyleSheet::remove_owning_document_or_shadow_root(DOM::Node& document_or_shadow_root)
 {
     m_owning_documents_or_shadow_roots.remove(document_or_shadow_root);
+
+    for (auto const& import_rule : m_import_rules) {
+        if (import_rule->loaded_style_sheet())
+            import_rule->loaded_style_sheet()->remove_owning_document_or_shadow_root(document_or_shadow_root);
+    }
 }
 
 void CSSStyleSheet::invalidate_owners(DOM::StyleInvalidationReason reason)
@@ -342,11 +352,6 @@ GC::Ptr<DOM::Document> CSSStyleSheet::owning_document() const
     if (!m_owning_documents_or_shadow_roots.is_empty())
         return (*m_owning_documents_or_shadow_roots.begin())->document();
 
-    if (m_owner_css_rule && m_owner_css_rule->parent_style_sheet()) {
-        if (auto document = m_owner_css_rule->parent_style_sheet()->owning_document())
-            return document;
-    }
-
     if (auto* element = const_cast<CSSStyleSheet*>(this)->owner_node())
         return element->document();
 
diff --git a/Libraries/LibWeb/CSS/CSSStyleSheet.h b/Libraries/LibWeb/CSS/CSSStyleSheet.h
index da5e7e55ed2..638b3896984 100644
--- a/Libraries/LibWeb/CSS/CSSStyleSheet.h
+++ b/Libraries/LibWeb/CSS/CSSStyleSheet.h
@@ -66,6 +66,7 @@ public:
     bool evaluate_media_queries(DOM::Document const&);
     void for_each_effective_keyframes_at_rule(Function<void(CSSKeyframesRule const&)> const& callback) const;
 
+    HashTable<GC::Ptr<DOM::Node>> owning_documents_or_shadow_roots() const { return m_owning_documents_or_shadow_roots; }
     void add_owning_document_or_shadow_root(DOM::Node& document_or_shadow_root);
     void remove_owning_document_or_shadow_root(DOM::Node& document_or_shadow_root);
     void invalidate_owners(DOM::StyleInvalidationReason);