diff --git a/target/product/aosp_product.mk b/target/product/aosp_product.mk
index f22c3a31f2..a3da1c9319 100644
--- a/target/product/aosp_product.mk
+++ b/target/product/aosp_product.mk
@@ -23,9 +23,9 @@ $(call inherit-product-if-exists, frameworks/base/data/sounds/AllAudio.mk)
 
 # Additional settings used in all AOSP builds
 PRODUCT_PRODUCT_PROPERTIES += \
-    ro.config.ringtone=Ring_Synth_04.ogg \
-    ro.config.notification_sound=pixiedust.ogg \
-    ro.com.android.dataroaming=true \
+    ro.config.ringtone?=Ring_Synth_04.ogg \
+    ro.config.notification_sound?=pixiedust.ogg \
+    ro.com.android.dataroaming?=true \
 
 # More AOSP packages
 PRODUCT_PACKAGES += \
diff --git a/target/product/full_base.mk b/target/product/full_base.mk
index dfb22047ee..64f61ffbcb 100644
--- a/target/product/full_base.mk
+++ b/target/product/full_base.mk
@@ -43,8 +43,8 @@ PRODUCT_PACKAGES += \
 
 # Additional settings used in all AOSP builds
 PRODUCT_VENDOR_PROPERTIES := \
-    ro.config.ringtone=Ring_Synth_04.ogg \
-    ro.config.notification_sound=pixiedust.ogg
+    ro.config.ringtone?=Ring_Synth_04.ogg \
+    ro.config.notification_sound?=pixiedust.ogg
 
 # Put en_US first in the list, so make it default.
 PRODUCT_LOCALES := en_US
diff --git a/target/product/full_base_telephony.mk b/target/product/full_base_telephony.mk
index 5e18c058c7..d8a54cd7f3 100644
--- a/target/product/full_base_telephony.mk
+++ b/target/product/full_base_telephony.mk
@@ -20,8 +20,8 @@
 # entirely appropriate to inherit from for on-device configurations.
 
 PRODUCT_VENDOR_PROPERTIES := \
-    keyguard.no_require_sim=true \
-    ro.com.android.dataroaming=true
+    keyguard.no_require_sim?=true \
+    ro.com.android.dataroaming?=true
 
 PRODUCT_COPY_FILES := \
     device/sample/etc/apns-full-conf.xml:system/etc/apns-conf.xml \
diff --git a/target/product/handheld_system.mk b/target/product/handheld_system.mk
index 22c817e54b..e2c91b666b 100644
--- a/target/product/handheld_system.mk
+++ b/target/product/handheld_system.mk
@@ -84,6 +84,6 @@ PRODUCT_COPY_FILES += \
     frameworks/av/media/libeffects/data/audio_effects.conf:system/etc/audio_effects.conf
 
 PRODUCT_VENDOR_PROPERTIES += \
-    ro.carrier=unknown \
-    ro.config.notification_sound=OnTheHunt.ogg \
-    ro.config.alarm_alert=Alarm_Classic.ogg
+    ro.carrier?=unknown \
+    ro.config.notification_sound?=OnTheHunt.ogg \
+    ro.config.alarm_alert?=Alarm_Classic.ogg
diff --git a/target/product/media_system.mk b/target/product/media_system.mk
index a3fafb3426..7a2dd73e76 100644
--- a/target/product/media_system.mk
+++ b/target/product/media_system.mk
@@ -74,7 +74,7 @@ PRODUCT_COPY_FILES += $(call add-to-product-copy-files-if-exists,\
 # On userdebug builds, collect more tombstones by default.
 ifneq (,$(filter userdebug eng,$(TARGET_BUILD_VARIANT)))
 PRODUCT_VENDOR_PROPERTIES += \
-    tombstoned.max_tombstone_count=50
+    tombstoned.max_tombstone_count?=50
 endif
 
 PRODUCT_VENDOR_PROPERTIES += \