diff --git a/.gitmodules b/.gitmodules
index bfea1ec298..75a68d2e94 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -1,5 +1,5 @@
 [submodule "firmware/ChibiOS"]
-	path = firmware/ChibiOS3
+	path = firmware/ChibiOS4
 	url = https://github.com/rusefi/ChibiOS.git
 	branch = stable_17.6.rusefi
 [submodule "firmware/ChibiOS-Contrib"]
diff --git a/firmware/ChibiOS3 b/firmware/ChibiOS4
similarity index 100%
rename from firmware/ChibiOS3
rename to firmware/ChibiOS4
diff --git a/firmware/Makefile b/firmware/Makefile
index 22dc4d5341..04433bc6dd 100644
--- a/firmware/Makefile
+++ b/firmware/Makefile
@@ -103,7 +103,7 @@ PROJECT = rusefi
 PROJECT_DIR = .
 
 # Imported source files and paths
-CHIBIOS = ChibiOS3
+CHIBIOS = ChibiOS4
 CHIBIOS_CONTRIB = ChibiOS-Contrib
 
 ifeq ($(PROJECT_BOARD),)
diff --git a/simulator/Makefile b/simulator/Makefile
index 4ea70f2e97..c23d5f6fd2 100644
--- a/simulator/Makefile
+++ b/simulator/Makefile
@@ -74,7 +74,7 @@ PROJECT = rusefi_simulator
 PROJECT_DIR = ../firmware
 
 # Imported source files and paths
-CHIBIOS = ../firmware/ChibiOS3
+CHIBIOS = ../firmware/ChibiOS4
 
 # Startup files.
 # HAL-OSAL files (optional).
diff --git a/unit_tests/Makefile b/unit_tests/Makefile
index 83c9d6e2a8..ef7fc64eb5 100644
--- a/unit_tests/Makefile
+++ b/unit_tests/Makefile
@@ -131,7 +131,7 @@ TCPPSRC =
 # List ASM source files here
 ASMSRC = $(PORTASM)
 
-CHIBIOS=$(PROJECT_DIR)/ChibiOS3
+CHIBIOS=$(PROJECT_DIR)/ChibiOS4
 
 INCDIR = . \
 	$(PROJECT_DIR)/util \