diff --git a/platformio_esp32_envs.ini b/platformio_esp32_envs.ini
index dfb9aca1b..8f842a532 100644
--- a/platformio_esp32_envs.ini
+++ b/platformio_esp32_envs.ini
@@ -15,6 +15,7 @@ board_build.f_flash       = 80000000L
 board_build.flash_mode    = dout
 board_upload.maximum_size = 1900544
 board_build.partitions    = esp32_partition_app1810k_spiffs316k.csv
+extra_scripts             = post:post_esp32.py
 build_unflags             = -Wall
 build_flags               = ${mqtt_flags.build_flags} 
                             -D BUILD_GIT='"${sysenv.TRAVIS_TAG}"' 
@@ -30,14 +31,15 @@ extends                   = esp32_common
 platform                  = ${esp32_common.platform}
 build_flags               = ${esp32_common.build_flags}   -DPLUGIN_BUILD_CUSTOM
 board                     = esp32dev
-extra_scripts             = pre:pre_custom_esp32.py
-
+extra_scripts             = ${esp32_common.extra_scripts}
+                            pre:pre_custom_esp32.py
 
 [env:test_ESP32_4M316k]
 extends                   = esp32_common
 platform                  = ${esp32_common.platform}
 build_flags               = ${esp32_common.build_flags}  -DPLUGIN_SET_TEST_ESP32
 board                     = esp32dev
+extra_scripts             = ${esp32_common.extra_scripts}
 
 
 [env:test_ESP32-wrover-kit_4M316k]
@@ -48,5 +50,6 @@ board                     = esp-wrover-kit
 upload_protocol           = ftdi
 debug_tool                = ftdi
 debug_extra_cmds          = break Misc.ino:3011
+extra_scripts             = ${esp32_common.extra_scripts}
 
 
diff --git a/post_esp32.py b/post_esp32.py
new file mode 100755
index 000000000..49952f5d3
--- /dev/null
+++ b/post_esp32.py
@@ -0,0 +1,23 @@
+Import("env")
+
+def after_build(source, target, env):
+    print("Generating factory bin for genuine esp units")
+    #offset = 0x1000
+    offset = 0x0
+    new_file_name = env.subst("$BUILD_DIR/${PROGNAME}-factory.bin")
+    sections = env.subst(env.get('FLASH_EXTRA_IMAGES'))
+    new_file = open(new_file_name,"wb")
+    for section in sections:
+      sect_adr,sect_file = section.split(" ")
+      source = open(sect_file,"rb")
+      new_file.seek(int(sect_adr,0)-offset)
+      new_file.write(source.read());
+      source.close()
+    
+    firmware = open(env.subst("$BUILD_DIR/${PROGNAME}.bin"),"rb")
+    new_file.seek(0x10000-offset)
+    new_file.write(firmware.read())
+    new_file.close()
+    firmware.close()
+
+env.AddPostAction("$BUILD_DIR/${PROGNAME}.bin", after_build)