diff --git a/serialportcommander/devicepluginserialportcommander.cpp b/serialportcommander/devicepluginserialportcommander.cpp
index 0ddec3b2..71b832f2 100644
--- a/serialportcommander/devicepluginserialportcommander.cpp
+++ b/serialportcommander/devicepluginserialportcommander.cpp
@@ -197,7 +197,6 @@ void DevicePluginSerialPortCommander::deviceRemoved(Device *device)
         serialPortCommander->removeInputDevice(device);
         if (serialPortCommander->isEmpty()) {
             m_serialPortCommanders.remove(interface);
-            serialPortCommander->serialPort()->close();
             serialPortCommander->deleteLater();
         }
     }
@@ -208,7 +207,6 @@ void DevicePluginSerialPortCommander::deviceRemoved(Device *device)
         serialPortCommander->removeOutputDevice();
         if (serialPortCommander->isEmpty()) {
             m_serialPortCommanders.remove(interface);
-            serialPortCommander->serialPort()->close();
             serialPortCommander->deleteLater();
         }
     }
diff --git a/serialportcommander/serialportcommander.cpp b/serialportcommander/serialportcommander.cpp
index 7ebde253..6c3d4800 100644
--- a/serialportcommander/serialportcommander.cpp
+++ b/serialportcommander/serialportcommander.cpp
@@ -45,7 +45,7 @@ void SerialPortCommander::addOutputDevice(Device* device)
 
 void SerialPortCommander::removeOutputDevice()
 {
-    m_outputDevice = NULL;
+    m_outputDevice = nullptr;
 }
 
 
@@ -63,7 +63,7 @@ void SerialPortCommander::removeInputDevice(Device* device)
 
 bool SerialPortCommander::isEmpty()
 {
-    return(!hasOutputDevice() || m_inputDevices.empty());
+    return(!hasOutputDevice() && m_inputDevices.empty());
 }