diff --git a/drivers/AnalogIn.h b/drivers/AnalogIn.h
index 38c1fc1..dd5d067 100644
--- a/drivers/AnalogIn.h
+++ b/drivers/AnalogIn.h
@@ -151,7 +151,9 @@
 
     virtual ~AnalogIn()
     {
-        // Do nothing
+        lock();
+        analogin_free(&_adc);
+        unlock();
     }
 
 protected:
diff --git a/drivers/QSPI.h b/drivers/QSPI.h
index 1ef8df2..f98fb45 100644
--- a/drivers/QSPI.h
+++ b/drivers/QSPI.h
@@ -117,6 +117,9 @@
 
     virtual ~QSPI()
     {
+        lock();
+        qspi_free(&_qspi);
+        unlock();
     }
 
     /** Configure the data transmission format
diff --git a/drivers/source/SerialBase.cpp b/drivers/source/SerialBase.cpp
index b335f69..40bf7d0 100644
--- a/drivers/source/SerialBase.cpp
+++ b/drivers/source/SerialBase.cpp
@@ -287,6 +287,10 @@
     for (int irq = 0; irq < IrqCnt; irq++) {
         attach(nullptr, (IrqType)irq);
     }
+
+    if (_rx_enabled || _tx_enabled) {
+        serial_free(&_serial);
+    }
 }
 
 #if DEVICE_SERIAL_FC