diff --git a/docs/pyboard/tutorial/repl.rst b/docs/pyboard/tutorial/repl.rst
index 646ecbc23736d6a78397e2d585b3743c21bba79c..3853b1578567b1bb449401650e74f8f7d63692fe 100644
--- a/docs/pyboard/tutorial/repl.rst
+++ b/docs/pyboard/tutorial/repl.rst
@@ -96,8 +96,8 @@ If something goes wrong, you can reset the board in two ways. The first is to pr
 at the MicroPython prompt, which performs a soft reset.  You will see a message something like ::
 
     >>> 
-    PYB: sync filesystems
-    PYB: soft reboot
+    MPY: sync filesystems
+    MPY: soft reboot
     Micro Python v1.0 on 2014-05-03; PYBv1.0 with STM32F405RG
     Type "help()" for more information.
     >>>
diff --git a/docs/reference/repl.rst b/docs/reference/repl.rst
index 1eccb9a88a1df90ba43f1cd13aa5dea3f9beaf23..0c6f04b7c5090f15c232ed5b3ba6a975fa6e1bc1 100644
--- a/docs/reference/repl.rst
+++ b/docs/reference/repl.rst
@@ -174,8 +174,8 @@ variables no longer exist:
 
 .. code-block:: python
 
-    PYB: sync filesystems
-    PYB: soft reboot
+    MPY: sync filesystems
+    MPY: soft reboot
     MicroPython v1.5-51-g6f70283-dirty on 2015-10-30; PYBv1.0 with STM32F405RG
     Type "help()" for more information.
     >>> dir()
diff --git a/docs/wipy/tutorial/repl.rst b/docs/wipy/tutorial/repl.rst
index e25e0472c59d7f11619afcf5f3004161965166f4..8c60e2c1d134b7527445c086ae158ba381b809dc 100644
--- a/docs/wipy/tutorial/repl.rst
+++ b/docs/wipy/tutorial/repl.rst
@@ -120,7 +120,7 @@ If something goes wrong, you can reset the board in two ways. The first is to pr
 at the MicroPython prompt, which performs a soft reset.  You will see a message something like::
 
     >>> 
-    PYB: soft reboot
+    MPY: soft reboot
     MicroPython v1.4.6-146-g1d8b5e5 on 2015-10-21; WiPy with CC3200
     Type "help()" for more information.
     >>>
diff --git a/lib/utils/pyexec.c b/lib/utils/pyexec.c
index b7174c9a13e4eefd9c7691d93c48613e979ad5b0..f4e6856e506faecc02b637a6f8536be1f55ec004 100644
--- a/lib/utils/pyexec.c
+++ b/lib/utils/pyexec.c
@@ -450,7 +450,7 @@ friendly_repl_reset:
             // do the user a favor and reenable interrupts.
             if (query_irq() == IRQ_STATE_DISABLED) {
                 enable_irq(IRQ_STATE_ENABLED);
-                mp_hal_stdout_tx_str("PYB: enabling IRQs\r\n");
+                mp_hal_stdout_tx_str("MPY: enabling IRQs\r\n");
             }
         }
         #endif
diff --git a/ports/cc3200/mptask.c b/ports/cc3200/mptask.c
index 9b6169342c1b714360ad0564a954093578958157..9390978474f796ce28d261f7e7534fc24d8361d6 100644
--- a/ports/cc3200/mptask.c
+++ b/ports/cc3200/mptask.c
@@ -234,7 +234,7 @@ soft_reset_exit:
 
     // soft reset
     pyb_sleep_signal_soft_reset();
-    mp_printf(&mp_plat_print, "PYB: soft reboot\n");
+    mp_printf(&mp_plat_print, "MPY: soft reboot\n");
 
     // disable all callbacks to avoid undefined behaviour
     // when coming out of a soft reset
diff --git a/ports/esp32/main.c b/ports/esp32/main.c
index a304dcbccf37fca47b04eede90a92d24fdb1edd2..188fb5e70dd3444f90ded371e35a8d0375f4c236 100644
--- a/ports/esp32/main.c
+++ b/ports/esp32/main.c
@@ -138,7 +138,7 @@ soft_reset:
 
     gc_sweep_all();
 
-    mp_hal_stdout_tx_str("PYB: soft reboot\r\n");
+    mp_hal_stdout_tx_str("MPY: soft reboot\r\n");
 
     // deinitialise peripherals
     machine_pins_deinit();
diff --git a/ports/esp8266/main.c b/ports/esp8266/main.c
index 923e4530fc427bc9ed22c81c8274a2b9c7e7153f..67157ce18c563a1b91283fa0ec43bea3dc48e648 100644
--- a/ports/esp8266/main.c
+++ b/ports/esp8266/main.c
@@ -86,7 +86,7 @@ STATIC void mp_reset(void) {
 
 void soft_reset(void) {
     gc_sweep_all();
-    mp_hal_stdout_tx_str("PYB: soft reboot\r\n");
+    mp_hal_stdout_tx_str("MPY: soft reboot\r\n");
     mp_hal_delay_us(10000); // allow UART to flush output
     mp_reset();
     #if MICROPY_REPL_EVENT_DRIVEN
diff --git a/ports/pic16bit/main.c b/ports/pic16bit/main.c
index 47ba00f48fdf1409dd53ed02700f8bd0f512062e..c96ac54ea4867336d1f785b48aca06fdca276adb 100644
--- a/ports/pic16bit/main.c
+++ b/ports/pic16bit/main.c
@@ -87,7 +87,7 @@ soft_reset:
         }
     }
 
-    printf("PYB: soft reboot\n");
+    printf("MPY: soft reboot\n");
     mp_deinit();
     goto soft_reset;
 }
diff --git a/ports/stm32/main.c b/ports/stm32/main.c
index 3028f907b6eebc8825c4f13f882535b9da0d3b75..8a65188ed1863c0b21c7dfcd4423be7a103cd7d7 100644
--- a/ports/stm32/main.c
+++ b/ports/stm32/main.c
@@ -203,7 +203,7 @@ MP_NOINLINE STATIC bool init_flash_fs(uint reset_mode) {
         if (res == FR_OK) {
             // success creating fresh LFS
         } else {
-            printf("PYB: can't create flash filesystem\n");
+            printf("MPY: can't create flash filesystem\n");
             return false;
         }
 
@@ -235,7 +235,7 @@ MP_NOINLINE STATIC bool init_flash_fs(uint reset_mode) {
         // mount sucessful
     } else {
     fail:
-        printf("PYB: can't mount flash\n");
+        printf("MPY: can't mount flash\n");
         return false;
     }
 
@@ -349,7 +349,7 @@ STATIC bool init_sdcard_fs(void) {
     }
 
     if (first_part) {
-        printf("PYB: can't mount SD card\n");
+        printf("MPY: can't mount SD card\n");
         return false;
     } else {
         return true;
@@ -763,11 +763,11 @@ soft_reset_exit:
     // soft reset
 
     #if MICROPY_HW_ENABLE_STORAGE
-    printf("PYB: sync filesystems\n");
+    printf("MPY: sync filesystems\n");
     storage_flush();
     #endif
 
-    printf("PYB: soft reboot\n");
+    printf("MPY: soft reboot\n");
     #if MICROPY_PY_NETWORK
     mod_network_deinit();
     #endif
diff --git a/ports/teensy/main.c b/ports/teensy/main.c
index 3ae049883fa744a3277887f853f6530467de0519..ad98a436440098867363f201d8193173ad014724 100644
--- a/ports/teensy/main.c
+++ b/ports/teensy/main.c
@@ -343,7 +343,7 @@ soft_reset:
         }
     }
 
-    printf("PYB: soft reboot\n");
+    printf("MPY: soft reboot\n");
 
 //    first_soft_reset = false;
     goto soft_reset;