diff --git a/lib/tapioca/gem/pipeline.rb b/lib/tapioca/gem/pipeline.rb
index ccf22fe5c..f7d3cf74a 100644
--- a/lib/tapioca/gem/pipeline.rb
+++ b/lib/tapioca/gem/pipeline.rb
@@ -31,8 +31,10 @@ def initialize(
         @events = [] #: Array[Gem::Event]
 
         @payload_symbols = Static::SymbolLoader.payload_symbols #: Set[String]
-        @bootstrap_symbols = load_bootstrap_symbols(@gem) #: Set[String]
-        gem_graph = Static::SymbolLoader.graph_from_paths(@gem.files) if include_doc
+        gem_graph = Static::SymbolLoader.graph_from_paths(@gem.files) #: Rubydex::Graph
+        gem_symbols = Static::SymbolLoader.symbols_from_graph(gem_graph)
+        engine_symbols = Static::SymbolLoader.engine_symbols(@gem)
+        @bootstrap_symbols = gem_symbols.union(engine_symbols) #: Set[String]
 
         @bootstrap_symbols.each { |symbol| push_symbol(symbol) }
 
@@ -191,14 +193,6 @@ def name_of(constant)
 
       private
 
-      #: (Gemfile::GemSpec gem) -> Set[String]
-      def load_bootstrap_symbols(gem)
-        engine_symbols = Static::SymbolLoader.engine_symbols(gem)
-        gem_symbols = Static::SymbolLoader.gem_symbols(gem)
-
-        gem_symbols.union(engine_symbols)
-      end
-
       # Events handling
 
       #: -> Gem::Event
diff --git a/lib/tapioca/static/symbol_loader.rb b/lib/tapioca/static/symbol_loader.rb
index 7f0c08b09..a070f9a29 100644
--- a/lib/tapioca/static/symbol_loader.rb
+++ b/lib/tapioca/static/symbol_loader.rb
@@ -26,9 +26,26 @@ def graph_from_paths(paths)
           graph
         end
 
-        #: (Gemfile::GemSpec gem) -> Set[String]
-        def gem_symbols(gem)
-          symbols_from_paths(gem.files)
+        #: (Rubydex::Graph graph) -> Set[String]
+        def symbols_from_graph(graph)
+          graph.declarations.filter_map do |decl|
+            next unless decl.is_a?(Rubydex::Namespace) ||
+              decl.is_a?(Rubydex::Constant) ||
+              decl.is_a?(Rubydex::ConstantAlias) ||
+              decl.is_a?(Rubydex::Todo)
+
+            # Declarations added by `graph.resolve` only have `rubydex:built-in` definitions.
+            # We exclude those unless the namespace has method or constant members defined in
+            # source files, which indicates a class reopening (e.g. `class Object; def Nokogiri(); end`).
+            if decl.definitions.any? && decl.definitions.all? { |defn| defn.location.uri == "rubydex:built-in" }
+              next unless decl.is_a?(Rubydex::Namespace) && decl.members.any? do |m|
+                (m.is_a?(Rubydex::Method) || m.is_a?(Rubydex::Constant) || m.is_a?(Rubydex::ConstantAlias)) &&
+                  m.definitions.any?
+              end
+            end
+
+            decl.name
+          end.to_set
         end
 
         #: (Gemfile::GemSpec gem) -> Set[String]
@@ -51,7 +68,8 @@ def engine_symbols(gem)
             Pathname.glob("#{load_path}/**/*.rb")
           end
 
-          symbols_from_paths(paths)
+          engine_graph = graph_from_paths(paths)
+          symbols_from_graph(engine_graph)
         rescue
           Set.new
         end