diff --git a/core/definitions.mk b/core/definitions.mk
index abc6209..7409e37 100644
--- a/core/definitions.mk
+++ b/core/definitions.mk
@@ -140,7 +140,6 @@
 ###########################################################
 ## Remove any makefiles that are being handled by soong
 ###########################################################
-ifeq ($(USE_SOONG),true)
 define filter-soong-makefiles
 $(foreach mk,$(1),\
   $(if $(wildcard $(patsubst %/Android.mk,%/Android.bp,$(mk))),\
@@ -150,11 +149,6 @@
       $(info skipping $(mk) ...)),\
     $(mk)))
 endef
-else
-define filter-soong-makefiles
-$(1)
-endef
-endif
 
 ###########################################################
 ## Retrieve a list of all makefiles immediately below some directory
@@ -2600,36 +2594,6 @@
   $(hide) mkdir -p $(dir $(3)/$(s)); cp -Rf $(t) $(3)/$(s)$(newline))
 endef
 
-
-###########################################################
-## Commands to copy toolchain libraries
-###########################################################
-ifneq ($(USE_SOONG),true)
-# Used when Soong isn't defining our toolchain libraries
-# $(1): Name of library (libgcc, etc)
-define copy-toolchain-library
-$(call copy-toolchain-library-internal,\
-  $(call intermediates-dir-for,STATIC_LIBRARIES,$(1))/$(1).a,,$(1))
-ifdef TARGET_2ND_ARCH
-$(call copy-toolchain-library-internal,\
-  $(call intermediates-dir-for,STATIC_LIBRARIES,$(1),,,2ND_)/$(1).a,2ND_,$(1))
-endif
-endef
-
-# $(1): the intermediates library path
-# $(2): whether this is the 2nd target architecture
-# $(3): the name of the library without the extension
-define copy-toolchain-library-internal
-$(1): build/soong/scripts/copygcclib.sh $($(2)TARGET_CC)
-	@echo "Toolchain library: $(3)"
-	@mkdir -p $$(dir $$@)
-	$$(hide) rm -f $$@
-	$$(hide) build/soong/scripts/copygcclib.sh $$@ $($(2)TARGET_CC) $($(2)TARGET_GLOBAL_CFLAGS) -print-file-name=$(3).a
-
-$(call include-depfile,$(1).d,$(1))
-endef
-endif
-
 ###########################################################
 ## Commands to call Proguard
 ###########################################################
diff --git a/core/main.mk b/core/main.mk
index 83c60e5..56be9ae 100644
--- a/core/main.mk
+++ b/core/main.mk
@@ -97,9 +97,6 @@
 # and host information.
 include $(BUILD_SYSTEM)/config.mk
 
-# Default soong to on
-USE_SOONG ?= true
-
 ifndef KATI
 ifdef USE_NINJA
 $(warning USE_NINJA is ignored. Ninja is always used.)
@@ -291,12 +288,6 @@
 # Bring in standard build system definitions.
 include $(BUILD_SYSTEM)/definitions.mk
 
-ifneq ($(USE_SOONG),true)
-$(eval $(call copy-toolchain-library,libgcc))
-$(eval $(call copy-toolchain-library,libatomic))
-$(eval $(call copy-toolchain-library,libgcov))
-endif
-
 # Bring in dex_preopt.mk
 include $(BUILD_SYSTEM)/dex_preopt.mk
 
@@ -556,9 +547,7 @@
 subdir_makefiles := \
 	$(shell build/tools/findleaves.py $(FIND_LEAVES_EXCLUDES) $(subdirs) Android.mk)
 
-ifeq ($(USE_SOONG),true)
 subdir_makefiles := $(SOONG_ANDROID_MK) $(call filter-soong-makefiles,$(subdir_makefiles))
-endif
 
 $(foreach mk, $(subdir_makefiles),$(info including $(mk) ...)$(eval include $(mk)))
 
@@ -899,9 +888,8 @@
 
 .PHONY: checkbuild
 checkbuild: $(modules_to_check) droid_targets
-ifeq ($(USE_SOONG),true)
 checkbuild: checkbuild-soong
-endif
+
 ifeq (true,$(ANDROID_BUILD_EVERYTHING_BY_DEFAULT))
 droid: checkbuild
 endif
diff --git a/core/ninja.mk b/core/ninja.mk
index 5136f4e..589affe 100644
--- a/core/ninja.mk
+++ b/core/ninja.mk
@@ -127,16 +127,12 @@
 
 NINJA_ARGS += $(NINJA_EXTRA_ARGS)
 
-ifeq ($(USE_SOONG),true)
 COMBINED_BUILD_NINJA := $(OUT_DIR)/combined$(KATI_NINJA_SUFFIX).ninja
 
 $(COMBINED_BUILD_NINJA): $(KATI_BUILD_NINJA)
 	$(hide) echo "builddir = $(OUT_DIR)" > $(COMBINED_BUILD_NINJA)
 	$(hide) echo "subninja $(SOONG_BUILD_NINJA)" >> $(COMBINED_BUILD_NINJA)
 	$(hide) echo "subninja $(KATI_BUILD_NINJA)" >> $(COMBINED_BUILD_NINJA)
-else
-COMBINED_BUILD_NINJA := $(KATI_BUILD_NINJA)
-endif
 
 $(sort $(DEFAULT_GOAL) $(ANDROID_GOALS)) : ninja_wrapper
 	@#empty
diff --git a/core/soong.mk b/core/soong.mk
index 032efdf..2f36be9 100644
--- a/core/soong.mk
+++ b/core/soong.mk
@@ -5,12 +5,7 @@
 SOONG_IN_MAKE := $(SOONG_OUT_DIR)/.soong.in_make
 SOONG_MAKEVARS_MK := $(SOONG_OUT_DIR)/make_vars-$(TARGET_PRODUCT).mk
 SOONG_VARIABLES := $(SOONG_OUT_DIR)/soong.variables
-
-# Only include the Soong-generated Android.mk if we're merging the
-# Soong-defined binaries with Kati-defined binaries.
-ifeq ($(USE_SOONG),true)
 SOONG_ANDROID_MK := $(SOONG_OUT_DIR)/Android-$(TARGET_PRODUCT).mk
-endif
 
 # We need to rebootstrap soong if SOONG_OUT_DIR or the reverse path from
 # SOONG_OUT_DIR to TOP changes