diff --git a/tools/mpremote/mpremote/transport_serial.py b/tools/mpremote/mpremote/transport_serial.py
index 6f43e2c41..28ccaf6d8 100644
--- a/tools/mpremote/mpremote/transport_serial.py
+++ b/tools/mpremote/mpremote/transport_serial.py
@@ -121,7 +121,7 @@ class SerialTransport(Transport):
         return data
 
     def enter_raw_repl(self, soft_reset=True):
-        self.serial.write(b"\r\x03\x03")  # ctrl-C twice: interrupt any running program
+        self.serial.write(b"\r\x03")  # ctrl-C: interrupt any running program
 
         # flush input (without relying on serial.flushInput())
         n = self.serial.inWaiting()
diff --git a/tools/pyboard.py b/tools/pyboard.py
index 55cbe8384..8459bcf65 100755
--- a/tools/pyboard.py
+++ b/tools/pyboard.py
@@ -348,7 +348,7 @@ class Pyboard:
         return data
 
     def enter_raw_repl(self, soft_reset=True):
-        self.serial.write(b"\r\x03\x03")  # ctrl-C twice: interrupt any running program
+        self.serial.write(b"\r\x03")  # ctrl-C: interrupt any running program
 
         # flush input (without relying on serial.flushInput())
         n = self.serial.inWaiting()