diff --git a/gems/smithy-client/lib/smithy-client/features.rb b/gems/smithy-client/lib/smithy-client/features.rb
index f60321fd6..262e312f8 100644
--- a/gems/smithy-client/lib/smithy-client/features.rb
+++ b/gems/smithy-client/lib/smithy-client/features.rb
@@ -6,15 +6,16 @@ module Client
     module Features
       class << self
         def track(*features, &block)
-          Thread.current[:smithy_ruby_features] ||= []
-          Thread.current[:smithy_ruby_features].concat(features)
+          Thread.current[:smithy_ruby_features] ||= Set.new
+          added = features.map { |f| Thread.current[:smithy_ruby_features].add?(f) }
           block.call
         ensure
-          Thread.current[:smithy_ruby_features].pop(features.size)
+          features.each_with_index { |f, i| Thread.current[:smithy_ruby_features].delete(f) if added[i] }
         end
 
         def tracked
-          Thread.current[:smithy_ruby_features] || []
+          Thread.current[:smithy_ruby_features] || Set.new
+          Thread.current[:smithy_ruby_features].to_a
         end
       end
     end
diff --git a/gems/smithy-client/spec/smithy-client/features_spec.rb b/gems/smithy-client/spec/smithy-client/features_spec.rb
index 6f89bbaed..df0f21839 100644
--- a/gems/smithy-client/spec/smithy-client/features_spec.rb
+++ b/gems/smithy-client/spec/smithy-client/features_spec.rb
@@ -57,6 +57,17 @@ module Client
         end
         expect(Features.tracked).to be_empty
       end
+
+      it 'does not track duplicate features' do
+        Features.track('A', 'B') do
+          expect(Features.tracked).to eq(%w[A B])
+          Features.track('A') do
+            expect(Features.tracked).to eq(%w[A B])
+          end
+          expect(Features.tracked).to eq(%w[A B])
+        end
+        expect(Features.tracked).to be_empty
+      end
     end
   end
 end
diff --git a/projections/shapes/lib/shapes/client.rb b/projections/shapes/lib/shapes/client.rb
index 455cceec2..68c72a96e 100644
--- a/projections/shapes/lib/shapes/client.rb
+++ b/projections/shapes/lib/shapes/client.rb
@@ -161,8 +161,7 @@ class Client < Smithy::Client::Base
     # @option options [Boolean] :stub_responses
     #  When `true`, the client will return stubbed responses instead of networking requests.
     #  By default fake responses are generated and returned. You can specify the response data
-    #  to return or errors to raise by calling {Stubs#stub_responses}.
-    #  @see Stubs
+    #  to return or errors to raise by calling {Smithy::Client::Stubs#stub_responses}.
     # @option options [String] :user_agent_suffix
     #  An optional string that is appended to the User-Agent header.
     #  The default User-Agent includes the smithy-client version,
diff --git a/projections/weather/lib/weather/client.rb b/projections/weather/lib/weather/client.rb
index 059e2f5cc..1136a3d93 100644
--- a/projections/weather/lib/weather/client.rb
+++ b/projections/weather/lib/weather/client.rb
@@ -161,8 +161,7 @@ class Client < Smithy::Client::Base
     # @option options [Boolean] :stub_responses
     #  When `true`, the client will return stubbed responses instead of networking requests.
     #  By default fake responses are generated and returned. You can specify the response data
-    #  to return or errors to raise by calling {Stubs#stub_responses}.
-    #  @see Stubs
+    #  to return or errors to raise by calling {Smithy::Client::Stubs#stub_responses}.
     # @option options [String] :user_agent_suffix
     #  An optional string that is appended to the User-Agent header.
     #  The default User-Agent includes the smithy-client version,