diff --git a/src/include/ipxe/efi/efi.h b/src/include/ipxe/efi/efi.h
index d3415532..48ec0968 100644
--- a/src/include/ipxe/efi/efi.h
+++ b/src/include/ipxe/efi/efi.h
@@ -214,6 +214,7 @@ extern EFI_HANDLE efi_image_handle;
 extern EFI_LOADED_IMAGE_PROTOCOL *efi_loaded_image;
 extern EFI_DEVICE_PATH_PROTOCOL *efi_loaded_image_path;
 extern EFI_SYSTEM_TABLE *efi_systab;
+extern int efi_shutdown_in_progress;
 
 extern const __attribute__ (( pure )) char * efi_guid_ntoa ( EFI_GUID *guid );
 extern const __attribute__ (( pure )) char *
diff --git a/src/interface/efi/efi_init.c b/src/interface/efi/efi_init.c
index 93ada21d..cfaff606 100644
--- a/src/interface/efi/efi_init.c
+++ b/src/interface/efi/efi_init.c
@@ -35,6 +35,9 @@ EFI_LOADED_IMAGE_PROTOCOL *efi_loaded_image;
 /** System table passed to entry point */
 EFI_SYSTEM_TABLE *efi_systab;
 
+/** EFI shutdown is in progress */
+int efi_shutdown_in_progress;
+
 /** Event used to signal shutdown */
 static EFI_EVENT efi_shutdown_event;
 
@@ -50,6 +53,13 @@ static EFI_STATUS EFIAPI efi_unload ( EFI_HANDLE image_handle );
  */
 static EFIAPI void efi_shutdown_hook ( EFI_EVENT event __unused,
 				       void *context __unused ) {
+
+	/* Mark shutdown as being in progress, to indicate that large
+	 * parts of the system (e.g. timers) are no longer functional.
+	 */
+	efi_shutdown_in_progress = 1;
+
+	/* Shut down iPXE */
 	shutdown_boot();
 }
 
diff --git a/src/interface/efi/efi_timer.c b/src/interface/efi/efi_timer.c
index da064120..1fd9971e 100644
--- a/src/interface/efi/efi_timer.c
+++ b/src/interface/efi/efi_timer.c
@@ -70,6 +70,31 @@ static void efi_udelay ( unsigned long usecs ) {
  */
 static unsigned long efi_currticks ( void ) {
 
+	/* EFI provides no clean way for device drivers to shut down
+	 * in preparation for handover to a booted operating system.
+	 * The platform firmware simply doesn't bother to call the
+	 * drivers' Stop() methods.  Instead, drivers must register an
+	 * EVT_SIGNAL_EXIT_BOOT_SERVICES event to be signalled when
+	 * ExitBootServices() is called, and clean up without any
+	 * reference to the EFI driver model.
+	 *
+	 * Unfortunately, all timers silently stop working when
+	 * ExitBootServices() is called.  Even more unfortunately, and
+	 * for no discernible reason, this happens before any
+	 * EVT_SIGNAL_EXIT_BOOT_SERVICES events are signalled.  The
+	 * net effect of this entertaining design choice is that any
+	 * timeout loops on the shutdown path (e.g. for gracefully
+	 * closing outstanding TCP connections) may wait indefinitely.
+	 *
+	 * There is no way to report failure from currticks(), since
+	 * the API lazily assumes that the host system continues to
+	 * travel through time in the usual direction.  Work around
+	 * EFI's violation of this assumption by falling back to a
+	 * simple free-running monotonic counter.
+	 */
+	if ( efi_shutdown_in_progress )
+		efi_jiffies++;
+
 	return efi_jiffies;
 }