diff --git a/Firmware/Src/syscalls.c b/Firmware/Src/syscalls.c
index 3cd2a073..1b8e7589 100644
--- a/Firmware/Src/syscalls.c
+++ b/Firmware/Src/syscalls.c
@@ -5,7 +5,9 @@
   ******************************************************************************
 */
 
-#include  <sys/unistd.h>
+#include <sys/unistd.h>
+#include <cmsis_os.h>
+#include <freertos_vars.h>
 #include <usbd_cdc_if.h>
 #include <usart.h>
 #include <commands.h>
@@ -19,6 +21,8 @@
 
 #define UART_TX_BUFFER_SIZE 64
 static uint8_t uart_tx_buf[UART_TX_BUFFER_SIZE];
+extern PCD_HandleTypeDef hpcd_USB_OTG_FS;
+extern USBD_HandleTypeDef hUsbDeviceFS;
 
 int _write(int file, char *data, int len) {
   //number of bytes written
@@ -49,5 +53,15 @@ int _write(int file, char *data, int len) {
     } break;
   }
 
+  // Wait for transmission to complete
+  USBD_CDC_HandleTypeDef* hcdc = (USBD_CDC_HandleTypeDef*)hUsbDeviceFS.pClassData;
+  while (hcdc->TxState != 0) {
+      osSemaphoreWait(sem_usb_irq, 0);
+      // We have a new incoming USB transmission: handle it
+      HAL_PCD_IRQHandler(&hpcd_USB_OTG_FS);
+      // Let the irq (OTG_FS_IRQHandler) fire again.
+      HAL_NVIC_EnableIRQ(OTG_FS_IRQn);
+  }
+  
   return written;
 }