diff --git a/firmware/Makefile b/firmware/Makefile
index c3b183e1fb..80c4655af8 100644
--- a/firmware/Makefile
+++ b/firmware/Makefile
@@ -7,6 +7,8 @@ CHIBIOS = ChibiOS
 RULESPATH = $(CHIBIOS)/os/common/startup/ARMCMx/compilers/GCC
 RULESFILE = $(RULESPATH)/rules.mk
 
+include rusefi_rules.mk
+
 # Define project name here
 PROJECT = rusefi
 PROJECT_DIR = .
@@ -35,9 +37,12 @@ endif
 
 # Compiler options here.
 ifeq ($(USE_OPT),)
-  USE_OPT = $(EXTRA_PARAMS) $(DEBUG_LEVEL_OPT) $(RFLAGS) -Wno-error=implicit-fallthrough -Wno-error=bool-operation -fomit-frame-pointer -falign-functions=16 -Werror -Wno-error=pointer-sign -Wno-error=unused-function -Wno-error=unused-variable -Wno-error=sign-compare -Wno-error=unused-parameter -Werror=missing-field-initializers -Werror=type-limits -Wno-error=strict-aliasing -Wno-error=attributes
+  USE_OPT = $(EXTRA_PARAMS) $(DEBUG_LEVEL_OPT) $(RFLAGS) -Wno-error=implicit-fallthrough -Wno-error=bool-operation -fomit-frame-pointer -falign-functions=16 -Werror=type-limits -Wno-error=strict-aliasing -Wno-error=attributes
 endif
 
+
+USE_OPT += $(RUSEFI_OPT)
+
 # C specific options here (added to USE_OPT).
 ifeq ($(USE_COPT),)
   USE_COPT = -fgnu89-inline -std=gnu99 -Werror-implicit-function-declaration
diff --git a/firmware/rusefi_rules.mk b/firmware/rusefi_rules.mk
new file mode 100644
index 0000000000..4232098583
--- /dev/null
+++ b/firmware/rusefi_rules.mk
@@ -0,0 +1,5 @@
+RUSEFI_OPT=-Werror -Wno-error=pointer-sign -Wno-error=unused-function -Wno-error=unused-variable -Wno-error=sign-compare -Wno-error=unused-parameter -Werror=missing-field-initializers
+
+RUSEFI_OPT+=-Wno-error=missing-prototypes
+
+RUSEFI_OPT+=-Werror=switch
\ No newline at end of file
diff --git a/simulator/Makefile b/simulator/Makefile
index b221a477a8..fa3f5c360a 100644
--- a/simulator/Makefile
+++ b/simulator/Makefile
@@ -18,6 +18,8 @@ RULESPATH = $(CHIBIOS)/os/common/startup/SIMIA32/compilers/GCC
 RULESFILE = $(RULESPATH)/rules.mk
 
 include ../firmware/rusefi.mk
+RULESFILE = ../firmware/rusefi_rules.mk
+
 
 
 # Compiler options here.
@@ -28,7 +30,7 @@ ifeq ($(USE_OPT),)
 # this config producec a smaller binary file
 # 7.3 compiler would want -Wno-error=implicit-fallthrough while 6.4 does not know about it
 # see https://github.com/rusefi/rusefi/issues/517
-  USE_OPT = -Wall -O2    -Wno-error=implicit-fallthrough       -Werror-implicit-function-declaration -Werror -Wno-error=pointer-sign -Wno-error=unused-function -Wno-error=unused-variable -Wno-error=sign-compare -Wno-error=unused-parameter -Werror=missing-field-initializers -Wno-error=write-strings -Wno-error=strict-aliasing
+  USE_OPT = -Wall -O2    -Wno-error=implicit-fallthrough -Wno-error=write-strings -Wno-error=strict-aliasing
 
 	ifeq ($(OS),Windows_NT)
 	else
@@ -36,6 +38,8 @@ ifeq ($(USE_OPT),)
 	endif
 endif
 
+USE_OPT += $(RUSEFI_OPT)
+
 ifeq ($(CCACHE_DIR),)
  $(info No CCACHE_DIR)
 else