diff --git a/lib/rb/lib/thrift/server/nonblocking_server.rb b/lib/rb/lib/thrift/server/nonblocking_server.rb
index f2959f2fe16..8290bf2eb71 100644
--- a/lib/rb/lib/thrift/server/nonblocking_server.rb
+++ b/lib/rb/lib/thrift/server/nonblocking_server.rb
@@ -138,7 +138,12 @@ def shutdown(timeout = 0)
 
       def ensure_closed
         kill_worker_threads if @worker_threads
-        @iom_thread.kill
+        if @iom_thread&.alive?
+          @iom_thread.kill
+          @iom_thread.join
+        end
+        close_connections
+        close_signal_pipes
       end
 
       private
@@ -246,6 +251,26 @@ def kill_worker_threads
         @worker_threads.clear
       end
 
+      def close_connections
+        @connections.each do |fd|
+          begin
+            fd.close
+          rescue IOError, SystemCallError, TransportException
+          end
+        end
+        @connections.clear
+        @buffers.clear
+      end
+
+      def close_signal_pipes
+        @signal_pipes.each do |pipe|
+          begin
+            pipe.close unless pipe.closed?
+          rescue IOError
+          end
+        end
+      end
+
       def slice_frame!(buf)
         if buf.length >= 4
           size = buf.unpack('N').first
diff --git a/lib/rb/spec/nonblocking_server_spec.rb b/lib/rb/spec/nonblocking_server_spec.rb
index 572e0b5b018..58949e34920 100644
--- a/lib/rb/spec/nonblocking_server_spec.rb
+++ b/lib/rb/spec/nonblocking_server_spec.rb
@@ -101,7 +101,7 @@ def listen
 
   describe Thrift::NonblockingServer do
     before(:each) do
-      @port = 43251
+      @port = available_port
       handler = Handler.new
       processor = SpecNamespace::NonblockingService::Processor.new(handler)
       queue = Queue.new
@@ -121,6 +121,7 @@ def listen
         end
       end
       queue.pop
+      wait_until_listening(@transport, @server_thread)
 
       @clients = []
       @catch_exceptions = false
@@ -128,9 +129,11 @@ def listen
 
     after(:each) do
       @clients.each { |client, trans| trans.close }
-      # @server.shutdown(1)
-      @server_thread.kill
-      @transport.close
+      @server.shutdown(1, false) if @server
+      @server_thread.join(2) if @server_thread
+      @server_thread.kill if @server_thread && @server_thread.alive?
+      @server_thread.join(2) if @server_thread
+      @transport.close if @transport
     end
 
     def setup_client(queue = nil)
@@ -261,6 +264,70 @@ def setup_client_thread(result)
     end
   end
 
+  describe Thrift::NonblockingServer::IOManager do
+    def build_io_manager
+      logger = Logger.new(IO::NULL)
+      logger.level = Logger::FATAL
+      Thrift::NonblockingServer::IOManager.new(
+        double('processor'),
+        double('server_transport'),
+        Thrift::BaseTransportFactory.new,
+        Thrift::BinaryProtocolFactory.new,
+        1,
+        logger
+      )
+    end
+
+    it "closes tracked connections and signal pipes during forced cleanup" do
+      io_manager = build_io_manager
+      connection = double('connection', :close => nil)
+      pipe_a = double('pipe_a', :closed? => false, :close => nil)
+      pipe_b = double('pipe_b', :closed? => false, :close => nil)
+
+      io_manager.instance_variable_set(:@connections, [connection])
+      io_manager.instance_variable_set(:@buffers, { connection => 'frame' })
+      io_manager.instance_variable_set(:@signal_pipes, [pipe_a, pipe_b])
+      io_manager.instance_variable_set(:@worker_threads, [])
+
+      io_manager.ensure_closed
+
+      expect(connection).to have_received(:close)
+      expect(pipe_a).to have_received(:close)
+      expect(pipe_b).to have_received(:close)
+      expect(io_manager.instance_variable_get(:@connections)).to be_empty
+      expect(io_manager.instance_variable_get(:@buffers)).to be_empty
+    end
+
+    it "continues closing remaining signal pipes when one close raises" do
+      io_manager = build_io_manager
+      pipe_a = double('pipe_a', :closed? => false)
+      pipe_b = double('pipe_b', :closed? => false, :close => nil)
+
+      allow(pipe_a).to receive(:close).and_raise(IOError)
+
+      io_manager.instance_variable_set(:@signal_pipes, [pipe_a, pipe_b])
+      io_manager.instance_variable_set(:@worker_threads, [])
+
+      io_manager.send(:close_signal_pipes)
+
+      expect(pipe_a).to have_received(:close)
+      expect(pipe_b).to have_received(:close)
+    end
+
+    it "drops removed connections from bookkeeping" do
+      io_manager = build_io_manager
+      connection = double('connection', :close => nil)
+
+      io_manager.instance_variable_set(:@connections, [connection])
+      io_manager.instance_variable_set(:@buffers, { connection => 'frame' })
+
+      io_manager.send(:remove_connection, connection)
+
+      expect(io_manager.instance_variable_get(:@connections)).to be_empty
+      expect(io_manager.instance_variable_get(:@buffers)).to be_empty
+    end
+  end
+
   describe "#{Thrift::NonblockingServer} with TLS transport" do
     before(:each) do
       @port = available_port
@@ -282,7 +349,7 @@ def setup_client_thread(result)
       end
 
       @clients = []
-      wait_until_listening
+      wait_until_listening(@transport, @server_thread)
     end
 
     after(:each) do
@@ -313,19 +380,6 @@ def setup_tls_client
       client
     end
 
-    def wait_until_listening
-      Timeout.timeout(2) do
-        until @transport.handle
-          raise "Server thread exited unexpectedly" unless @server_thread.alive?
-          sleep 0.01
-        end
-      end
-    end
-
-    def available_port
-      TCPServer.open('localhost', 0) { |server| server.addr[1] }
-    end
-
     def ssl_keys_dir
       File.expand_path('../../../test/keys', __dir__)
     end
@@ -358,4 +412,17 @@ def create_client_ssl_context
       end
     end
   end
+
+  def wait_until_listening(server_transport, server_thread)
+    Timeout.timeout(2) do
+      until server_transport.handle
+        raise "Server thread exited unexpectedly" unless server_thread.alive?
+        sleep 0.01
+      end
+    end
+  end
+
+  def available_port
+    TCPServer.open('localhost', 0) { |server| server.addr[1] }
+  end
 end