diff --git a/simulator/Makefile b/simulator/Makefile
index 701c19cd69..fbc158f13c 100644
--- a/simulator/Makefile
+++ b/simulator/Makefile
@@ -3,12 +3,12 @@
 # NOTE: Can be overridden externally.
 #
 
-ifeq ("$(wildcard ../firmware/ChibiOS4/os/common/startup/ARMCMx/compilers/GCC/rules.mk)","")
-#
-# todo: someone please figure out the syntax to invoke 'git submodule update --init' from here
-#
-$(error Modules are missing? Did you execute 'git submodule update --init'?)
-endif
+
+CHIBIOS = ../firmware/ChibiOS4
+RULESPATH = $(CHIBIOS)/os/common/startup/SIMIA32/compilers/GCC
+RULESFILE = $(RULESPATH)/rules.mk
+
+include ../firmware/rusefi.mk
 
 
 # Compiler options here.
@@ -84,7 +84,6 @@ PROJECT = rusefi_simulator
 PROJECT_DIR = ../firmware
 
 # Imported source files and paths
-CHIBIOS = ../firmware/ChibiOS4
 
 # Startup files.
 # HAL-OSAL files (optional).
@@ -267,5 +266,4 @@ endif
 # End of user defines
 ##############################################################################
 
-RULESPATH = $(CHIBIOS)/os/common/startup/SIMIA32/compilers/GCC
 include $(RULESPATH)/rules.mk
diff --git a/unit_tests/Makefile b/unit_tests/Makefile
index d9129df54c..5d5ab94de5 100644
--- a/unit_tests/Makefile
+++ b/unit_tests/Makefile
@@ -4,7 +4,16 @@
 #
 
 PROJECT_DIR = ../firmware
-#CHIBIOS = $(PROJECT_DIR)/chibios
+CHIBIOS=$(PROJECT_DIR)/ChibiOS4
+STREAMSFILE = $(CHIBIOS)/os/hal/include/hal_streams.h
+
+ifeq ("$(wildcard $(STREAMSFILE))","")
+$(info Invoking "git submodule update --init")
+$(shell git submodule update --init)
+$(info Invoked "git submodule update --init")
+# make is not happy about newly checked out module for some reason but next invocation would work
+$(error Please run 'make' again)
+endif
 
 # Compiler options here.
 ifeq ($(USE_OPT),)
@@ -138,7 +147,6 @@ TCPPSRC =
 # List ASM source files here
 ASMSRC = $(PORTASM)
 
-CHIBIOS=$(PROJECT_DIR)/ChibiOS4
 
 INCDIR = . \
 	$(PROJECT_DIR)/util \