diff --git a/Changes.md b/Changes.md
index 53ff007..3e48bad 100644
--- a/Changes.md
+++ b/Changes.md
@@ -86,6 +86,11 @@
 $(TARGET): myscript.py $(sort $(shell find my/python/lib -name '*.py'))
 	PYTHONPATH=my/python/lib:$$PYTHONPATH myscript.py -o $@
 ```
+### Stop using PRODUCT_COMPATIBILITY_MATRIX_LEVEL_OVERRIDE directly {#PRODUCT_COMPATIBILITY_MATRIX_LEVEL_OVERRIDE}
+
+Specify Framework Compatibility Matrix Version in device manifest by adding a `target-level`
+attribute to the root element `<manifest>`. If `PRODUCT_COMPATIBILITY_MATRIX_LEVEL_OVERRIDE`
+is 26 or 27, you can add `"target-level"="1"` to your device manifest instead.
 
 ### Other envsetup.sh variables  {#other_envsetup_variables}
 
diff --git a/core/config.mk b/core/config.mk
index e43793a..d317bd0 100644
--- a/core/config.mk
+++ b/core/config.mk
@@ -75,6 +75,7 @@
   ANDROID_EMULATOR_PREBUILTS \
   ANDROID_PRE_BUILD_PATHS \
   ,See $(CHANGES_URL)#other_envsetup_variables)
+$(KATI_obsolete_var PRODUCT_COMPATIBILITY_MATRIX_LEVEL_OVERRIDE,Set FCM Version in device manifest instead. See $(CHANGES_URL)#PRODUCT_COMPATIBILITY_MATRIX_LEVEL_OVERRIDE)
 
 CHANGES_URL :=
 
@@ -784,44 +785,7 @@
 endif
 
 FRAMEWORK_MANIFEST_FILE := system/libhidl/manifest.xml
-
-# Compatibility matrix versioning:
-# MATRIX_LEVEL_OVERRIDE defined: MATRIX_LEVEL = MATRIX_LEVEL_OVERRIDE
-# MATRIX_LEVEL_OVERRIDE undefined:
-#   FULL_TREBLE != true: MATRIX_LEVEL = legacy
-#   FULL_TREBLE == true:
-#     SHIPPING_API_LEVEL defined: MATRIX_LEVEL = SHIPPING_API_LEVEL
-#     SHIPPING_API_LEVEL undefined: MATRIX_LEVEL = PLATFORM_SDK_VERSION
-# MATRIX_LEVEL == legacy => legacy.xml
-# MATRIX_LEVEL <= 26 => 26.xml
-# MATRIX_LEVEL == 27 => 27.xml # define when 27 releases
-# MATRIX_LEVEL == 28 => 28.xml # define when 28 releases
-# ...
-# otherwise => current.xml
-
-ifneq ($(PRODUCT_COMPATIBILITY_MATRIX_LEVEL_OVERRIDE),)
-  PRODUCT_COMPATIBILITY_MATRIX_LEVEL := $(PRODUCT_COMPATIBILITY_MATRIX_LEVEL_OVERRIDE)
-else ifneq ($(PRODUCT_FULL_TREBLE),true)
-  PRODUCT_COMPATIBILITY_MATRIX_LEVEL := legacy
-else ifneq ($(PRODUCT_SHIPPING_API_LEVEL),)
-  PRODUCT_COMPATIBILITY_MATRIX_LEVEL := $(PRODUCT_SHIPPING_API_LEVEL)
-else
-  PRODUCT_COMPATIBILITY_MATRIX_LEVEL := $(PLATFORM_SDK_VERSION)
-endif
-
-ifeq ($(strip $(PRODUCT_COMPATIBILITY_MATRIX_LEVEL)),legacy)
-  FRAMEWORK_COMPATIBILITY_MATRIX_FILE := hardware/interfaces/compatibility_matrix.legacy.xml
-else ifeq ($(call math_gt_or_eq,$(PRODUCT_COMPATIBILITY_MATRIX_LEVEL),26),)
-  # All PRODUCT_FULL_TREBLE devices with shipping API levels < 26 get the level 26 manifest
-  # as that is the first.
-  FRAMEWORK_COMPATIBILITY_MATRIX_FILE := hardware/interfaces/compatibility_matrix.26.xml
-else ifeq ($(call math_gt_or_eq,$(PRODUCT_COMPATIBILITY_MATRIX_LEVEL),28),)
-  # All shipping API levels with released compatibility matrices get the corresponding matrix.
-  FRAMEWORK_COMPATIBILITY_MATRIX_FILE := \
-      hardware/interfaces/compatibility_matrix.$(PRODUCT_COMPATIBILITY_MATRIX_LEVEL).xml
-else
-  FRAMEWORK_COMPATIBILITY_MATRIX_FILE := hardware/interfaces/compatibility_matrix.current.xml
-endif
+FRAMEWORK_COMPATIBILITY_MATRIX_FILES := $(wildcard hardware/interfaces/compatibility_matrix.*.xml)
 
 BUILD_NUMBER_FROM_FILE := $$(cat $(OUT_DIR)/build_number.txt)
 BUILD_DATETIME_FROM_FILE := $$(cat $(OUT_DIR)/build_date.txt)
diff --git a/target/board/Android.mk b/target/board/Android.mk
index 789651c..fc32cd9 100644
--- a/target/board/Android.mk
+++ b/target/board/Android.mk
@@ -43,6 +43,8 @@
 $(GEN): PRIVATE_DEVICE_MANIFEST_FILE := $(DEVICE_MANIFEST_FILE)
 $(GEN): $(DEVICE_MANIFEST_FILE) $(HOST_OUT_EXECUTABLES)/assemble_vintf
 	BOARD_SEPOLICY_VERS=$(BOARD_SEPOLICY_VERS) \
+	PRODUCT_ENFORCE_VINTF_MANIFEST=$(PRODUCT_ENFORCE_VINTF_MANIFEST) \
+	PRODUCT_SHIPPING_API_LEVEL=$(PRODUCT_SHIPPING_API_LEVEL) \
 	$(HOST_OUT_EXECUTABLES)/assemble_vintf -o $@ \
 		-i $(call normalize-path-list,$(PRIVATE_DEVICE_MANIFEST_FILE))
 
@@ -105,12 +107,10 @@
 
 $(GEN): PRIVATE_FLAGS :=
 
-ifeq ($(PRODUCT_ENFORCE_VINTF_MANIFEST),true)
 ifdef BUILT_VENDOR_MANIFEST
 $(GEN): $(BUILT_VENDOR_MANIFEST)
 $(GEN): PRIVATE_FLAGS += -c "$(BUILT_VENDOR_MANIFEST)"
 endif
-endif
 
 ifeq (true,$(BOARD_AVB_ENABLE))
 $(GEN): $(AVBTOOL)
@@ -141,12 +141,15 @@
 KERNEL_VERSIONS :=
 KERNEL_CONFIG_DATA :=
 
-$(GEN): $(FRAMEWORK_COMPATIBILITY_MATRIX_FILE) $(HOST_OUT_EXECUTABLES)/assemble_vintf
+$(GEN): $(FRAMEWORK_COMPATIBILITY_MATRIX_FILES) $(HOST_OUT_EXECUTABLES)/assemble_vintf
 	# TODO(b/37405869) (b/37715375) inject avb versions as well for devices that have avb enabled.
 	POLICYVERS=$(POLICYVERS) \
 		BOARD_SEPOLICY_VERS=$(BOARD_SEPOLICY_VERS) \
 		FRAMEWORK_VBMETA_VERSION=$(FRAMEWORK_VBMETA_VERSION) \
-		$(HOST_OUT_EXECUTABLES)/assemble_vintf -i $< -o $@ $(PRIVATE_FLAGS)
+		PRODUCT_ENFORCE_VINTF_MANIFEST=$(PRODUCT_ENFORCE_VINTF_MANIFEST) \
+		$(HOST_OUT_EXECUTABLES)/assemble_vintf \
+		-i $(call normalize-path-list,$(FRAMEWORK_COMPATIBILITY_MATRIX_FILES)) \
+		-o $@ $(PRIVATE_FLAGS)
 LOCAL_PREBUILT_MODULE_FILE := $(GEN)
 include $(BUILD_PREBUILT)
 BUILT_SYSTEM_COMPATIBILITY_MATRIX := $(LOCAL_BUILT_MODULE)