diff --git a/atusb/fw/flash.c b/atusb/fw/flash.c
index 1ed8b37..3aeea71 100644
--- a/atusb/fw/flash.c
+++ b/atusb/fw/flash.c
@@ -57,7 +57,15 @@ void flash_write(const uint8_t *buf, uint16_t size)
 			boot_spm_busy_wait();
 		}
         }
+}
 
+
+void flash_end_write(void)
+{
+	if (payload & (SPM_PAGESIZE-1)) {
+		boot_page_write(payload & ~(SPM_PAGESIZE-1));
+		boot_spm_busy_wait();
+	}
 	boot_rww_enable();
 }
 
diff --git a/atusb/fw/usb/dfu.c b/atusb/fw/usb/dfu.c
index 234dbb1..18eb98c 100644
--- a/atusb/fw/usb/dfu.c
+++ b/atusb/fw/usb/dfu.c
@@ -192,6 +192,7 @@ static int my_setup(const struct setup_request *setup)
 		}
 		if (!setup->wLength) {
 			debug("DONE\n");
+			flash_end_write();
 			dfu.state = dfuIDLE;
 			did_download = 1;
 			return 1;
diff --git a/atusb/fw/usb/dfu.h b/atusb/fw/usb/dfu.h
index a7469ea..152e297 100644
--- a/atusb/fw/usb/dfu.h
+++ b/atusb/fw/usb/dfu.h
@@ -84,6 +84,7 @@ extern struct dfu dfu;
 void flash_start(void);
 int flash_can_write(uint16_t size);
 void flash_write(const uint8_t *buf, uint16_t size);
+void flash_end_write(void);
 uint16_t flash_read(uint8_t *buf, uint16_t size);