diff --git a/code/espurna/dummy_ets_printf.c b/code/espurna/dummy_ets_printf.c
new file mode 100644
index 00000000..9519c8ba
--- /dev/null
+++ b/code/espurna/dummy_ets_printf.c
@@ -0,0 +1,4 @@
+// special dummy printf to disable Serial using some boards
+int dummy_ets_printf(const char* format, ...) {
+    return 0;
+}
diff --git a/code/extra_scripts.py b/code/extra_scripts.py
index de37bd31..1d8c4f6c 100644
--- a/code/extra_scripts.py
+++ b/code/extra_scripts.py
@@ -59,12 +59,12 @@ def remove_float_support():
         LINKFLAGS = newflags
     )
 
-def cpp_check(source, target, env):
+def cpp_check(target, source, env):
     print("Started cppcheck...\n")
     call(["cppcheck", os.getcwd()+"/espurna", "--force", "--enable=all"])
     print("Finished cppcheck...\n")
 
-def check_size(source, target, env):
+def check_size(target, source, env):
     (binary,) = target
     path = binary.get_abspath()
     size = os.stat(path).st_size
@@ -78,6 +78,20 @@ def check_size(source, target, env):
         print_warning("https://github.com/xoseperez/espurna/wiki/TwoStepUpdates", color=Color.LIGHT_CYAN)
         print_filler("*", color=Color.LIGHT_YELLOW, err=True)
 
+def dummy_ets_printf(target, source, env):
+    (postmortem_src_file, ) = source
+    (postmortem_obj_file, ) = target
+
+    cmd = ["xtensa-lx106-elf-objcopy"]
+
+    # recent Core switched to cpp+newlib & ets_printf_P
+    cmd.extend(["--redefine-sym", "ets_printf=dummy_ets_printf"])
+    cmd.extend(["--redefine-sym", "ets_printf_P=dummy_ets_printf"])
+
+    cmd.append(postmortem_obj_file.get_abspath())
+    env.Execute(env.VerboseAction(" ".join(cmd), "Removing ets_printf / ets_printf_P"))
+    env.Depends(postmortem_obj_file,"$BUILD_DIR/src/dummy_ets_printf.c.o")
+
 # ------------------------------------------------------------------------------
 # Hooks
 # ------------------------------------------------------------------------------
@@ -85,6 +99,13 @@ def check_size(source, target, env):
 # Always show warnings for project code
 projenv.ProcessUnFlags("-w")
 
+# 2.4.0 and up
 remove_float_support()
 
+# two-step update hint when using 1MB boards
 env.AddPostAction("$BUILD_DIR/${PROGNAME}.bin", check_size)
+
+# disable postmortem printing to the uart. another one is in eboot, but this is what causes the most harm
+if "DISABLE_POSTMORTEM_STACKDUMP" in env["CPPFLAGS"]:
+    env.AddPostAction("$BUILD_DIR/FrameworkArduino/core_esp8266_postmortem.c.o", dummy_ets_printf)
+    env.AddPostAction("$BUILD_DIR/FrameworkArduino/core_esp8266_postmortem.cpp.o", dummy_ets_printf)
diff --git a/code/platformio.ini b/code/platformio.ini
index 133c1702..bd3c8535 100644
--- a/code/platformio.ini
+++ b/code/platformio.ini
@@ -409,7 +409,7 @@ board = ${common.board_1m}
 board_build.flash_mode = ${common.flash_mode}
 lib_deps = ${common.lib_deps}
 lib_ignore = ${common.lib_ignore}
-build_flags = ${common.build_flags_1m0m} -DFOXEL_LIGHTFOX_DUAL
+build_flags = ${common.build_flags_1m0m} -DFOXEL_LIGHTFOX_DUAL -DDISABLE_POSTMORTEM_STACKDUMP
 extra_scripts = ${common.extra_scripts}
 
 [env:foxel-lightfox-dual-ota]
@@ -419,7 +419,7 @@ board = ${common.board_1m}
 board_build.flash_mode = ${common.flash_mode}
 lib_deps = ${common.lib_deps}
 lib_ignore = ${common.lib_ignore}
-build_flags = ${common.build_flags_1m0m} -DFOXEL_LIGHTFOX_DUAL
+build_flags = ${common.build_flags_1m0m} -DFOXEL_LIGHTFOX_DUAL -DDISABLE_POSTMORTEM_STACKDUMP
 upload_speed = ${common.upload_speed}
 upload_port = ${common.upload_port}
 upload_flags = ${common.upload_flags}
@@ -590,7 +590,7 @@ board = ${common.board_1m}
 board_build.flash_mode = ${common.flash_mode}
 lib_deps = ${common.lib_deps}
 lib_ignore = ${common.lib_ignore}
-build_flags = ${common.build_flags_1m0m} -DITEAD_SONOFF_POW_R2
+build_flags = ${common.build_flags_1m0m} -DITEAD_SONOFF_POW_R2 -DDISABLE_POSTMORTEM_STACKDUMP
 monitor_speed = ${common.monitor_speed}
 extra_scripts = ${common.extra_scripts}
 
@@ -601,7 +601,7 @@ board = ${common.board_1m}
 board_build.flash_mode = ${common.flash_mode}
 lib_deps = ${common.lib_deps}
 lib_ignore = ${common.lib_ignore}
-build_flags = ${common.build_flags_1m0m} -DITEAD_SONOFF_POW_R2
+build_flags = ${common.build_flags_1m0m} -DITEAD_SONOFF_POW_R2 -DDISABLE_POSTMORTEM_STACKDUMP
 upload_speed = ${common.upload_speed}
 upload_port = ${common.upload_port}
 upload_flags = ${common.upload_flags}
@@ -615,7 +615,7 @@ board = ${common.board_1m}
 board_build.flash_mode = ${common.flash_mode}
 lib_deps = ${common.lib_deps}
 lib_ignore = ${common.lib_ignore}
-build_flags = ${common.build_flags_1m0m} -DITEAD_SONOFF_DUAL
+build_flags = ${common.build_flags_1m0m} -DITEAD_SONOFF_DUAL -DDISABLE_POSTMORTEM_STACKDUMP
 extra_scripts = ${common.extra_scripts}
 
 [env:itead-sonoff-dual-ota]
@@ -625,7 +625,7 @@ board = ${common.board_1m}
 board_build.flash_mode = ${common.flash_mode}
 lib_deps = ${common.lib_deps}
 lib_ignore = ${common.lib_ignore}
-build_flags = ${common.build_flags_1m0m} -DITEAD_SONOFF_DUAL
+build_flags = ${common.build_flags_1m0m} -DITEAD_SONOFF_DUAL -DDISABLE_POSTMORTEM_STACKDUMP
 upload_speed = ${common.upload_speed}
 upload_port = ${common.upload_port}
 upload_flags = ${common.upload_flags}
@@ -861,7 +861,7 @@ board = ${common.board_1m}
 board_build.flash_mode = ${common.flash_mode}
 lib_deps = ${common.lib_deps}
 lib_ignore = ${common.lib_ignore}
-build_flags = ${common.build_flags_1m0m} -DITEAD_SONOFF_RFBRIDGE
+build_flags = ${common.build_flags_1m0m} -DITEAD_SONOFF_RFBRIDGE -DDISABLE_POSTMORTEM_STACKDUMP
 monitor_speed = 19200
 extra_scripts = ${common.extra_scripts}
 
@@ -872,7 +872,7 @@ board = ${common.board_1m}
 board_build.flash_mode = ${common.flash_mode}
 lib_deps = ${common.lib_deps}
 lib_ignore = ${common.lib_ignore}
-build_flags = ${common.build_flags_1m0m} -DITEAD_SONOFF_RFBRIDGE
+build_flags = ${common.build_flags_1m0m} -DITEAD_SONOFF_RFBRIDGE -DDISABLE_POSTMORTEM_STACKDUMP
 upload_speed = ${common.upload_speed}
 upload_port = ${common.upload_port}
 upload_flags = ${common.upload_flags}
@@ -1037,7 +1037,7 @@ board = ${common.board_1m}
 board_build.flash_mode = ${common.flash_mode}
 lib_deps = ${common.lib_deps}
 lib_ignore = ${common.lib_ignore}
-build_flags = ${common.build_flags_1m0m} -DITEAD_SONOFF_S31
+build_flags = ${common.build_flags_1m0m} -DITEAD_SONOFF_S31 -DDISABLE_POSTMORTEM_STACKDUMP
 monitor_speed = ${common.monitor_speed}
 extra_scripts = ${common.extra_scripts}
 
@@ -1048,7 +1048,7 @@ board = ${common.board_1m}
 board_build.flash_mode = ${common.flash_mode}
 lib_deps = ${common.lib_deps}
 lib_ignore = ${common.lib_ignore}
-build_flags = ${common.build_flags_1m0m} -DITEAD_SONOFF_S31
+build_flags = ${common.build_flags_1m0m} -DITEAD_SONOFF_S31 -DDISABLE_POSTMORTEM_STACKDUMP
 upload_port = ${common.upload_port}
 upload_flags = ${common.upload_flags}
 monitor_speed = ${common.monitor_speed}
@@ -2120,7 +2120,7 @@ board = ${common.board_1m}
 board_build.flash_mode = ${common.flash_mode}
 lib_deps = ${common.lib_deps}
 lib_ignore = ${common.lib_ignore}
-build_flags = ${common.build_flags_1m0m} -DSTM_RELAY
+build_flags = ${common.build_flags_1m0m} -DSTM_RELAY -DDISABLE_POSTMORTEM_STACKDUMP
 monitor_speed = ${common.monitor_speed}
 extra_scripts = ${common.extra_scripts}
 
@@ -2131,7 +2131,7 @@ board = ${common.board_1m}
 board_build.flash_mode = ${common.flash_mode}
 lib_deps = ${common.lib_deps}
 lib_ignore = ${common.lib_ignore}
-build_flags = ${common.build_flags_1m0m} -DSTM_RELAY
+build_flags = ${common.build_flags_1m0m} -DSTM_RELAY -DDISABLE_POSTMORTEM_STACKDUMP
 upload_speed = ${common.upload_speed}
 upload_port = ${common.upload_port}
 upload_flags = ${common.upload_flags}