diff --git a/fastboot/engine.cpp b/fastboot/engine.cpp
index 6a52b12..d80e986 100644
--- a/fastboot/engine.cpp
+++ b/fastboot/engine.cpp
@@ -88,7 +88,9 @@
 }
 
 void fb_reinit(Transport* transport) {
-    fb->set_transport(transport);
+    if (Transport* old_transport = fb->set_transport(transport)) {
+        delete old_transport;
+    }
 }
 
 const std::string fb_get_error() {
@@ -392,6 +394,6 @@
     }
     fprintf(stderr, "OKAY\n");
 
-    fb->set_transport(nullptr);
+    fb_reinit(nullptr);
     return true;
 }
diff --git a/fastboot/fastboot.cpp b/fastboot/fastboot.cpp
index 2887d3b..1aef567 100644
--- a/fastboot/fastboot.cpp
+++ b/fastboot/fastboot.cpp
@@ -1847,6 +1847,10 @@
 
     int status = fb_execute_queue() ? EXIT_FAILURE : EXIT_SUCCESS;
     fprintf(stderr, "Finished. Total time: %.3fs\n", (now() - start));
+
+    if (Transport* old_transport = fb.set_transport(nullptr)) {
+        delete old_transport;
+    }
     return status;
 }
 
diff --git a/fastboot/fastboot_driver.cpp b/fastboot/fastboot_driver.cpp
index ceee066..6bd6128 100644
--- a/fastboot/fastboot_driver.cpp
+++ b/fastboot/fastboot_driver.cpp
@@ -58,7 +58,6 @@
 }
 
 FastBootDriver::~FastBootDriver() {
-    set_transport(nullptr);
 }
 
 RetCode FastBootDriver::Boot(std::string* response, std::vector<std::string>* info) {
@@ -537,12 +536,9 @@
     return 0;
 }
 
-void FastBootDriver::set_transport(Transport* transport) {
-    if (transport_) {
-        transport_->Close();
-        delete transport_;
-    }
-    transport_ = transport;
+Transport* FastBootDriver::set_transport(Transport* transport) {
+    std::swap(transport_, transport);
+    return transport;
 }
 
 }  // End namespace fastboot
diff --git a/fastboot/fastboot_driver.h b/fastboot/fastboot_driver.h
index 4647945..2651690 100644
--- a/fastboot/fastboot_driver.h
+++ b/fastboot/fastboot_driver.h
@@ -109,8 +109,8 @@
     std::string Error();
     RetCode WaitForDisconnect();
 
-    // Note: changing the transport will close and delete the existing one.
-    void set_transport(Transport* transport);
+    // Note: set_transport will return the previous transport.
+    Transport* set_transport(Transport* transport);
     Transport* transport() const { return transport_; }
 
     // This is temporarily public for engine.cpp
diff --git a/fastboot/fuzzy_fastboot/fixtures.cpp b/fastboot/fuzzy_fastboot/fixtures.cpp
index 0a87598..4da71ca 100644
--- a/fastboot/fuzzy_fastboot/fixtures.cpp
+++ b/fastboot/fuzzy_fastboot/fixtures.cpp
@@ -133,7 +133,6 @@
     fb.reset();
 
     if (transport) {
-        transport->Close();
         transport.reset();
     }
 
@@ -188,7 +187,6 @@
         ASSERT_EQ(fb->RawCommand("flashing " + cmd, &resp), SUCCESS)
                 << "Attempting to change locked state, but 'flashing" + cmd + "' command failed";
         fb.reset();
-        transport->Close();
         transport.reset();
         printf("PLEASE RESPOND TO PROMPT FOR '%sing' BOOTLOADER ON DEVICE\n", cmd.c_str());
         while (UsbStillAvailible())
@@ -249,7 +247,6 @@
     }
 
     if (transport) {
-        transport->Close();
         transport.reset();
     }
 
diff --git a/fastboot/fuzzy_fastboot/usb_transport_sniffer.cpp b/fastboot/fuzzy_fastboot/usb_transport_sniffer.cpp
index ee510e9..7c595f4 100644
--- a/fastboot/fuzzy_fastboot/usb_transport_sniffer.cpp
+++ b/fastboot/fuzzy_fastboot/usb_transport_sniffer.cpp
@@ -12,6 +12,10 @@
                                          const int serial_fd)
     : transport_(std::move(transport)), serial_fd_(serial_fd) {}
 
+UsbTransportSniffer::~UsbTransportSniffer() {
+    Close();
+}
+
 ssize_t UsbTransportSniffer::Read(void* data, size_t len) {
     ProcessSerial();
 
diff --git a/fastboot/fuzzy_fastboot/usb_transport_sniffer.h b/fastboot/fuzzy_fastboot/usb_transport_sniffer.h
index 693f042..89cc009 100644
--- a/fastboot/fuzzy_fastboot/usb_transport_sniffer.h
+++ b/fastboot/fuzzy_fastboot/usb_transport_sniffer.h
@@ -68,6 +68,7 @@
     };
 
     UsbTransportSniffer(std::unique_ptr<UsbTransport> transport, const int serial_fd = 0);
+    ~UsbTransportSniffer() override;
 
     virtual ssize_t Read(void* data, size_t len) override;
     virtual ssize_t Write(const void* data, size_t len) override;
diff --git a/fastboot/usb_linux.cpp b/fastboot/usb_linux.cpp
index 9b779dd..6363aa5 100644
--- a/fastboot/usb_linux.cpp
+++ b/fastboot/usb_linux.cpp
@@ -95,7 +95,7 @@
   public:
     explicit LinuxUsbTransport(std::unique_ptr<usb_handle> handle, uint32_t ms_timeout = 0)
         : handle_(std::move(handle)), ms_timeout_(ms_timeout) {}
-    ~LinuxUsbTransport() override = default;
+    ~LinuxUsbTransport() override;
 
     ssize_t Read(void* data, size_t len) override;
     ssize_t Write(const void* data, size_t len) override;
@@ -387,6 +387,10 @@
     return usb;
 }
 
+LinuxUsbTransport::~LinuxUsbTransport() {
+    Close();
+}
+
 ssize_t LinuxUsbTransport::Write(const void* _data, size_t len)
 {
     unsigned char *data = (unsigned char*) _data;
diff --git a/fastboot/usb_osx.cpp b/fastboot/usb_osx.cpp
index 4d48f6e..ed02c4a 100644
--- a/fastboot/usb_osx.cpp
+++ b/fastboot/usb_osx.cpp
@@ -70,7 +70,7 @@
     // A timeout of 0 is blocking
     OsxUsbTransport(std::unique_ptr<usb_handle> handle, uint32_t ms_timeout = 0)
         : handle_(std::move(handle)), ms_timeout_(ms_timeout) {}
-    ~OsxUsbTransport() override = default;
+    ~OsxUsbTransport() override;
 
     ssize_t Read(void* data, size_t len) override;
     ssize_t Write(const void* data, size_t len) override;
@@ -471,6 +471,10 @@
     return new OsxUsbTransport(std::move(handle), timeout_ms);
 }
 
+OsxUsbTransport::~OsxUsbTransport() {
+    Close();
+}
+
 int OsxUsbTransport::Close() {
     /* TODO: Something better here? */
     return 0;
diff --git a/fastboot/usb_windows.cpp b/fastboot/usb_windows.cpp
index 8c60a71..b00edb3 100644
--- a/fastboot/usb_windows.cpp
+++ b/fastboot/usb_windows.cpp
@@ -69,7 +69,7 @@
 class WindowsUsbTransport : public UsbTransport {
   public:
     WindowsUsbTransport(std::unique_ptr<usb_handle> handle) : handle_(std::move(handle)) {}
-    ~WindowsUsbTransport() override = default;
+    ~WindowsUsbTransport() override;
 
     ssize_t Read(void* data, size_t len) override;
     ssize_t Write(const void* data, size_t len) override;
@@ -250,6 +250,10 @@
     }
 }
 
+WindowsUsbTransport::~WindowsUsbTransport() {
+    Close();
+}
+
 int WindowsUsbTransport::Close() {
     DBG("usb_close\n");