diff --git a/core/Makefile b/core/Makefile
index 5262475..3794d2b 100644
--- a/core/Makefile
+++ b/core/Makefile
@@ -685,7 +685,7 @@
 # for future OTA packages installed by this system.  Actual product
 # deliverables will be re-signed by hand.  We expect this file to
 # exist with the suffixes ".x509.pem" and ".pk8".
-DEFAULT_KEY_CERT_PAIR := $(DEFAULT_SYSTEM_DEV_CERTIFICATE)
+DEFAULT_KEY_CERT_PAIR := $(strip $(DEFAULT_SYSTEM_DEV_CERTIFICATE))
 
 
 # Rules that need to be present for the all targets, even
@@ -1140,12 +1140,12 @@
 # This rule adds to ALL_DEFAULT_INSTALLED_MODULES, so it needs to come
 # before the rules that use that variable to build the image.
 ALL_DEFAULT_INSTALLED_MODULES += $(TARGET_OUT_ETC)/security/otacerts.zip
-$(TARGET_OUT_ETC)/security/otacerts.zip: KEY_CERT_PAIR := $(DEFAULT_KEY_CERT_PAIR)
-$(TARGET_OUT_ETC)/security/otacerts.zip: $(addsuffix .x509.pem,$(DEFAULT_KEY_CERT_PAIR)) | $(ZIPTIME)
+$(TARGET_OUT_ETC)/security/otacerts.zip: PRIVATE_CERT := $(DEFAULT_KEY_CERT_PAIR).x509.pem
+$(TARGET_OUT_ETC)/security/otacerts.zip: $(SOONG_ZIP)
+$(TARGET_OUT_ETC)/security/otacerts.zip: $(DEFAULT_KEY_CERT_PAIR).x509.pem
 	$(hide) rm -f $@
 	$(hide) mkdir -p $(dir $@)
-	$(hide) zip -qjX $@ $<
-	$(remove-timestamps-from-package)
+	$(hide) $(SOONG_ZIP) -o $@ -C $(dir $(PRIVATE_CERT)) -f $(PRIVATE_CERT)
 
 # Carry the public key for update_engine if it's a non-IoT target that
 # uses the AB updater. We use the same key as otacerts but in RSA public key
@@ -1153,7 +1153,7 @@
 ifeq ($(AB_OTA_UPDATER),true)
 ifneq ($(PRODUCT_IOT),true)
 ALL_DEFAULT_INSTALLED_MODULES += $(TARGET_OUT_ETC)/update_engine/update-payload-key.pub.pem
-$(TARGET_OUT_ETC)/update_engine/update-payload-key.pub.pem: $(addsuffix .x509.pem,$(DEFAULT_KEY_CERT_PAIR))
+$(TARGET_OUT_ETC)/update_engine/update-payload-key.pub.pem: $(DEFAULT_KEY_CERT_PAIR).x509.pem
 	$(hide) rm -f $@
 	$(hide) mkdir -p $(dir $@)
 	$(hide) openssl x509 -pubkey -noout -in $< > $@
@@ -3141,15 +3141,15 @@
   $(sort $(shell find external/vboot_reference/tests/devkeys -type f))
 endif
 
-$(BUILT_OTATOOLS_PACKAGE): $(OTATOOLS) $(OTATOOLS_DEPS) $(OTATOOLS_RELEASETOOLS) | $(ACP)
+$(BUILT_OTATOOLS_PACKAGE): $(OTATOOLS) $(OTATOOLS_DEPS) $(OTATOOLS_RELEASETOOLS) $(SOONG_ZIP)
 	@echo "Package OTA tools: $@"
 	$(hide) rm -rf $@ $(zip_root)
 	$(hide) mkdir -p $(dir $@) $(zip_root)/bin $(zip_root)/framework $(zip_root)/releasetools
 	$(call copy-files-with-structure,$(OTATOOLS),$(HOST_OUT)/,$(zip_root))
-	$(hide) $(ACP) -r -d -p build/make/tools/releasetools/* $(zip_root)/releasetools
+	$(hide) cp -r -d -p build/make/tools/releasetools/* $(zip_root)/releasetools
 	$(hide) rm -rf $@ $(zip_root)/releasetools/*.pyc
-	$(hide) (cd $(zip_root) && zip -qryX $(abspath $@) *)
-	$(hide) echo $(OTATOOLS_DEPS) | xargs zip -qryX $(abspath $@)>/dev/null || true
+	$(hide) $(SOONG_ZIP) -o $@ -C $(zip_root) -D $(zip_root) \
+	  -C . $(addprefix -f ,$(OTATOOLS_DEPS))
 
 .PHONY: otatools-package
 otatools-package: $(BUILT_OTATOOLS_PACKAGE)