diff --git a/Source/serial.cpp b/Source/serial.cpp
index 9e3edd0..ff4ce71 100644
--- a/Source/serial.cpp
+++ b/Source/serial.cpp
@@ -17,10 +17,10 @@ extern "C" int _write(int file, char *ptr, int len)
 
   for (DataIdx = 0; DataIdx < len; DataIdx++)
   {
-    if(LL_LPUART_IsActiveFlag_TXE_TXFNF(LPUART1))
+    while(!LL_LPUART_IsActiveFlag_TXE_TXFNF(LPUART1))
     {
-      LL_LPUART_TransmitData8(LPUART1, static_cast<std::uint8_t>(*ptr++));
     }
+    LL_LPUART_TransmitData8(LPUART1, static_cast<std::uint8_t>(*ptr++));
   }
   return len;
 }