diff --git a/lib/jazzy/sourcekitten.rb b/lib/jazzy/sourcekitten.rb
index d7c857655..8cbc45eda 100644
--- a/lib/jazzy/sourcekitten.rb
+++ b/lib/jazzy/sourcekitten.rb
@@ -621,7 +621,7 @@ def self.make_source_declarations(docs, parent = nil, mark = SourceMark.new)
         declaration.inherited_types =
           inherited_types.map { |type| type['key.name'] }.compact
         declaration.async =
-          doc['key.async'] ||
+          doc['key.symgraph_async'] ||
           if xml_declaration = doc['key.fully_annotated_decl']
             swift_async?(xml_declaration)
           end
@@ -834,7 +834,9 @@ def self.mark_and_merge_protocol_extensions(protocol, extensions)
       extensions.each do |ext|
         ext.children = ext.children.select do |ext_member|
           proto_member = protocol.children.find do |p|
-            p.name == ext_member.name && p.type == ext_member.type
+            p.name == ext_member.name &&
+              p.type == ext_member.type &&
+              p.async == ext_member.async
           end
 
           # Extension-only method, keep.
diff --git a/lib/jazzy/symbol_graph/sym_node.rb b/lib/jazzy/symbol_graph/sym_node.rb
index 7272b7431..4b307ca96 100644
--- a/lib/jazzy/symbol_graph/sym_node.rb
+++ b/lib/jazzy/symbol_graph/sym_node.rb
@@ -140,7 +140,7 @@ def to_sourcekit
           'key.accessibility' => symbol.acl,
           'key.parsed_decl' => declaration,
           'key.annotated_decl' => xml_declaration,
-          'key.async' => async?,
+          'key.symgraph_async' => async?,
         }
         if docs = symbol.doc_comments
           hash['key.doc.comment'] = docs
diff --git a/spec/integration_specs b/spec/integration_specs
index ea09fef96..89154be14 160000
--- a/spec/integration_specs
+++ b/spec/integration_specs
@@ -1 +1 @@
-Subproject commit ea09fef96548cb366bb6c72870b7dc7c390b1a09
+Subproject commit 89154be14daa39df11cb5a87062a61fc3aa4c436