diff --git a/src/main/drivers/serial.c b/src/main/drivers/serial.c
index cacfd1dd4..bb81d3dd8 100644
--- a/src/main/drivers/serial.c
+++ b/src/main/drivers/serial.c
@@ -40,12 +40,17 @@ void serialWrite(serialPort_t *instance, uint8_t ch)
     instance->vTable->serialWrite(instance, ch);
 }
 
-void serialWriteBuf(serialPort_t *instance, void *data, int count)
+
+void serialWriteBuf(serialPort_t *instance, uint8_t *data, int count)
 {
     if (instance->vTable->writeBuf) {
         instance->vTable->writeBuf(instance, data, count);
     } else {
         for (uint8_t *p = data; count > 0; count--, p++) {
+
+            while (!serialTxBytesFree(instance)) {
+            };
+
             serialWrite(instance, *p);
         }
     }
@@ -81,7 +86,7 @@ void serialSetMode(serialPort_t *instance, portMode_t mode)
     instance->vTable->setMode(instance, mode);
 }
 
-void serialWriteBufShim(void *instance, void *data, int count)
+void serialWriteBufShim(void *instance, uint8_t *data, int count)
 {
     serialWriteBuf((serialPort_t *)instance, data, count);
 }