diff --git a/esptool/loader.py b/esptool/loader.py
index 5f2ff60a1..31a6555d5 100644
--- a/esptool/loader.py
+++ b/esptool/loader.py
@@ -341,11 +341,13 @@ def __init__(
                         if not printed_failure:
                             print(e)
                             print("Retrying to open port ", end="")
+                            sys.stdout.flush()
                             printed_failure = True
                         else:
                             if retry_attempts % 9 == 0:
                                 # print a dot every second
                                 print(".", end="")
+                                sys.stdout.flush()
                         time.sleep(0.1)
                         retry_attempts += 1
                         continue