diff --git a/tools/upload.py b/tools/upload.py
index 0f5cb78352..3567e0af21 100755
--- a/tools/upload.py
+++ b/tools/upload.py
@@ -24,8 +24,17 @@
 write_option = ''
 erase_addr = ''
 erase_len = ''
+compatibility = False 
 
-while len(sys.argv):
+arg_counter = len(sys.argv)-1
+while (arg_counter):
+    if sys.argv[arg_counter] == '--end':
+        compatibility = True
+        break 
+    arg_counter -= 1
+	
+
+while len(sys.argv) and not compatibility:	
     thisarg = sys.argv.pop(0)
 
     # We silently replace the 921kbaud setting with 460k to enable backward
@@ -52,10 +61,14 @@
     if len(thisarg):
         cmdline = cmdline + [thisarg]
 
-cmdline = cmdline + ['write_flash']
+if not compatibility:
+    cmdline = cmdline + ['write_flash']
+	
 if len(write_option):
     cmdline = cmdline + [write_option]
-cmdline = cmdline + ['0x0', binary]
+
+if not compatibility:
+    cmdline = cmdline + ['0x0', binary]
 
 erase_file = ''
 if len(erase_addr):
@@ -66,7 +79,25 @@
     os.close(eraser[0])
     cmdline = cmdline + [ erase_addr, erase_file ]
 
-esptool.main(cmdline)
+if not compatibility:
+    #sys.stderr.write("\ncmdline:" + str(cmdline) + "\n")
+    esptool.main(cmdline)
+
+while len(sys.argv) and compatibility:
+    if sys.argv[0] == '--end':
+	    #sys.stderr.write("\ncmdline:" + str(cmdline) + " in compatibility mode\n")
+	    esptool.main(cmdline)
+	    sys.argv.pop(0) # Remove --end
+	    cmdline = []
+    else:
+        # We silently replace the 921kbaud setting with 460k to enable backward
+        # compatibility with the old esptool-ck.exe.  Esptool.py doesn't seem
+        # work reliably at 921k, but is still significantly faster at 460kbaud.
+        thisarg = sys.argv.pop(0)
+        if thisarg == "921600":
+            thisarg = "460800"
+        cmdline = cmdline + [thisarg]
+
 
 if len(erase_file):
     os.remove(erase_file)