diff --git a/core/Makefile b/core/Makefile
index d66855a..c35f744 100644
--- a/core/Makefile
+++ b/core/Makefile
@@ -106,7 +106,7 @@
 BUILD_VERSION_TAGS := $(subst $(space),$(comma),$(sort $(BUILD_VERSION_TAGS)))
 
 # A human-readable string that descibes this build in detail.
-build_desc := $(TARGET_PRODUCT)-$(TARGET_BUILD_VARIANT) $(PLATFORM_VERSION) $(BUILD_ID) $(BUILD_NUMBER) $(BUILD_VERSION_TAGS)
+build_desc := $(TARGET_PRODUCT)-$(TARGET_BUILD_VARIANT) $(PLATFORM_VERSION) $(BUILD_ID) $(BUILD_NUMBER_FROM_FILE) $(BUILD_VERSION_TAGS)
 $(INSTALLED_BUILD_PROP_TARGET): PRIVATE_BUILD_DESC := $(build_desc)
 
 # The string used to uniquely identify the combined build and product; used by the OTA server.
@@ -124,6 +124,9 @@
   $(error BUILD_FINGERPRINT cannot contain spaces: "$(BUILD_FINGERPRINT)")
 endif
 
+$(shell echo $(BUILD_FINGERPRINT) > $(PRODUCT_OUT)/build_fingerprint.txt)
+BUILD_FINGERPRINT_FROM_FILE := $$(cat $(PRODUCT_OUT)/build_fingerprint.txt)
+
 # The string used to uniquely identify the system build; used by the OTA server.
 # This purposefully excludes any product-specific variables.
 ifeq (,$(strip $(BUILD_THUMBPRINT)))
@@ -147,7 +150,7 @@
 
   # Dev. branches should have DISPLAY_BUILD_NUMBER set
   ifeq "true" "$(DISPLAY_BUILD_NUMBER)"
-    BUILD_DISPLAY_ID := $(BUILD_ID).$(BUILD_NUMBER) $(BUILD_KEYS)
+    BUILD_DISPLAY_ID := $(BUILD_ID).$(BUILD_NUMBER_FROM_FILE) $(BUILD_KEYS)
   else
     BUILD_DISPLAY_ID := $(BUILD_ID) $(BUILD_KEYS)
   endif
@@ -194,14 +197,14 @@
 			PRIVATE_BUILD_DESC="$(PRIVATE_BUILD_DESC)" \
 			BUILD_ID="$(BUILD_ID)" \
 			BUILD_DISPLAY_ID="$(BUILD_DISPLAY_ID)" \
-			BUILD_NUMBER="$(BUILD_NUMBER)" \
+			BUILD_NUMBER="$(BUILD_NUMBER_FROM_FILE)" \
 			PLATFORM_VERSION="$(PLATFORM_VERSION)" \
 			PLATFORM_SDK_VERSION="$(PLATFORM_SDK_VERSION)" \
 			PLATFORM_VERSION_CODENAME="$(PLATFORM_VERSION_CODENAME)" \
 			PLATFORM_VERSION_ALL_CODENAMES="$(PLATFORM_VERSION_ALL_CODENAMES)" \
 			BUILD_VERSION_TAGS="$(BUILD_VERSION_TAGS)" \
 			TARGET_BOOTLOADER_BOARD_NAME="$(TARGET_BOOTLOADER_BOARD_NAME)" \
-			BUILD_FINGERPRINT="$(BUILD_FINGERPRINT)" \
+			BUILD_FINGERPRINT="$(BUILD_FINGERPRINT_FROM_FILE)" \
 			$(if $(OEM_THUMBPRINT_PROPERTIES),BUILD_THUMBPRINT="$(BUILD_THUMBPRINT)") \
 			TARGET_BOARD_PLATFORM="$(TARGET_BOARD_PLATFORM)" \
 			TARGET_CPU_ABI_LIST="$(TARGET_CPU_ABI_LIST)" \
@@ -244,7 +247,7 @@
 	$(hide) echo > $@
 	$(hide) echo ro.vendor.build.date=`date`>>$@
 	$(hide) echo ro.vendor.build.date.utc=`date +%s`>>$@
-	$(hide) echo ro.vendor.build.fingerprint="$(BUILD_FINGERPRINT)">>$@
+	$(hide) echo ro.vendor.build.fingerprint="$(BUILD_FINGERPRINT_FROM_FILE)">>$@
 endif
 
 # ----------------------------------------------------------------
@@ -260,7 +263,7 @@
 	$(hide) echo > $@
 	$(hide) echo ro.bootimage.build.date=`date`>>$@
 	$(hide) echo ro.bootimage.build.date.utc=`date +%s`>>$@
-	$(hide) echo ro.bootimage.build.fingerprint="$(BUILD_FINGERPRINT)">>$@
+	$(hide) echo ro.bootimage.build.fingerprint="$(BUILD_FINGERPRINT_FROM_FILE)">>$@
 
 # -----------------------------------------------------------------
 # sdk-build.prop
diff --git a/core/definitions.mk b/core/definitions.mk
index a9d09ef..fad753f 100644
--- a/core/definitions.mk
+++ b/core/definitions.mk
@@ -1664,8 +1664,8 @@
     $(addprefix -G , $(PRIVATE_PROGUARD_OPTIONS_FILE)) \
     $(addprefix --min-sdk-version , $(PRIVATE_DEFAULT_APP_TARGET_SDK)) \
     $(addprefix --target-sdk-version , $(PRIVATE_DEFAULT_APP_TARGET_SDK)) \
-    $(if $(filter --version-code,$(PRIVATE_AAPT_FLAGS)),,$(addprefix --version-code , $(PLATFORM_SDK_VERSION))) \
-    $(if $(filter --version-name,$(PRIVATE_AAPT_FLAGS)),,$(addprefix --version-name , $(PLATFORM_VERSION)-$(BUILD_NUMBER))) \
+    $(if $(filter --version-code,$(PRIVATE_AAPT_FLAGS)),,--version-code $(PLATFORM_SDK_VERSION)) \
+    $(if $(filter --version-name,$(PRIVATE_AAPT_FLAGS)),,--version-name $(PLATFORM_VERSION)-$(BUILD_NUMBER_FROM_FILE)) \
     $(addprefix --rename-manifest-package , $(PRIVATE_MANIFEST_PACKAGE_NAME)) \
     $(addprefix --rename-instrumentation-target-package , $(PRIVATE_MANIFEST_INSTRUMENTATION_FOR))
 endef
@@ -1788,7 +1788,7 @@
         $(PRIVATE_CLASS_INTERMEDIATES_DIR)/$(subst .,/,$(pkg))))
 $(if $(PRIVATE_RMTYPEDEFS), $(hide) $(RMTYPEDEFS) -v $(PRIVATE_CLASS_INTERMEDIATES_DIR))
 $(if $(PRIVATE_JAR_MANIFEST), \
-    $(hide) sed -e 's/%BUILD_NUMBER%/$(BUILD_NUMBER)/' \
+    $(hide) sed -e "s/%BUILD_NUMBER%/$(BUILD_NUMBER_FROM_FILE)/" \
             $(PRIVATE_JAR_MANIFEST) > $(dir $@)/manifest.mf && \
         jar -cfm $@ $(dir $@)/manifest.mf \
             -C $(PRIVATE_CLASS_INTERMEDIATES_DIR) ., \
@@ -1990,7 +1990,7 @@
         $(PRIVATE_CLASS_INTERMEDIATES_DIR)/$(subst .,/,$(pkg))))
 $(if $(PRIVATE_RMTYPEDEFS), $(hide) $(RMTYPEDEFS) -v $(PRIVATE_CLASS_INTERMEDIATES_DIR))
 $(if $(PRIVATE_JAR_MANIFEST), \
-    $(hide) sed -e 's/%BUILD_NUMBER%/$(BUILD_NUMBER)/' \
+    $(hide) sed -e "s/%BUILD_NUMBER%/$(BUILD_NUMBER_FROM_FILE)/" \
             $(PRIVATE_JAR_MANIFEST) > $(dir $@)/manifest.mf && \
         jar -cfm $@ $(dir $@)/manifest.mf \
             -C $(PRIVATE_CLASS_INTERMEDIATES_DIR) ., \
@@ -2093,8 +2093,8 @@
     $(addprefix --min-sdk-version , $(PRIVATE_DEFAULT_APP_TARGET_SDK)) \
     $(addprefix --target-sdk-version , $(PRIVATE_DEFAULT_APP_TARGET_SDK)) \
     $(if $(filter --product,$(PRIVATE_AAPT_FLAGS)),,$(addprefix --product , $(TARGET_AAPT_CHARACTERISTICS))) \
-    $(if $(filter --version-code,$(PRIVATE_AAPT_FLAGS)),,$(addprefix --version-code , $(PLATFORM_SDK_VERSION))) \
-    $(if $(filter --version-name,$(PRIVATE_AAPT_FLAGS)),,$(addprefix --version-name , $(PLATFORM_VERSION)-$(BUILD_NUMBER))) \
+    $(if $(filter --version-code,$(PRIVATE_AAPT_FLAGS)),,--version-code $(PLATFORM_SDK_VERSION)) \
+    $(if $(filter --version-name,$(PRIVATE_AAPT_FLAGS)),,--version-name $(PLATFORM_VERSION)-$(BUILD_NUMBER_FROM_FILE)) \
     $(addprefix --rename-manifest-package , $(PRIVATE_MANIFEST_PACKAGE_NAME)) \
     $(addprefix --rename-instrumentation-target-package , $(PRIVATE_MANIFEST_INSTRUMENTATION_FOR)) \
     -F $@
diff --git a/core/droiddoc.mk b/core/droiddoc.mk
index 41f135c..0de1837 100644
--- a/core/droiddoc.mk
+++ b/core/droiddoc.mk
@@ -131,8 +131,8 @@
 	$(HOST_OUT_JAVA_LIBRARIES)/doclava$(COMMON_JAVA_PACKAGE_SUFFIX)
 
 $(full_target): PRIVATE_DOCLETPATH := $(HOST_OUT_JAVA_LIBRARIES)/jsilver$(COMMON_JAVA_PACKAGE_SUFFIX):$(HOST_OUT_JAVA_LIBRARIES)/doclava$(COMMON_JAVA_PACKAGE_SUFFIX)
-$(full_target): PRIVATE_CURRENT_BUILD := -hdf page.build $(BUILD_ID)-$(BUILD_NUMBER)
-$(full_target): PRIVATE_CURRENT_TIME :=  -hdf page.now "$(shell date "+%d %b %Y %k:%M")"
+$(full_target): PRIVATE_CURRENT_BUILD := -hdf page.build $(BUILD_ID)-$(BUILD_NUMBER_FROM_FILE)
+$(full_target): PRIVATE_CURRENT_TIME :=  -hdf page.now "$$(date "+%d %b %Y %k:%M")"
 $(full_target): PRIVATE_CUSTOM_TEMPLATE_DIR := $(LOCAL_DROIDDOC_CUSTOM_TEMPLATE_DIR)
 $(full_target): PRIVATE_IN_CUSTOM_ASSET_DIR := $(LOCAL_DROIDDOC_CUSTOM_TEMPLATE_DIR)/$(LOCAL_DROIDDOC_CUSTOM_ASSET_DIR)
 $(full_target): PRIVATE_OUT_ASSET_DIR := $(out_dir)/$(LOCAL_DROIDDOC_ASSET_DIR)
diff --git a/core/main.mk b/core/main.mk
index 7f561ab..7f22d76 100644
--- a/core/main.mk
+++ b/core/main.mk
@@ -93,6 +93,12 @@
 # and host information.
 include $(BUILD_SYSTEM)/config.mk
 
+# Write the build number to a file so it can be read back in
+# without changing the command line every time.  Avoids rebuilds
+# when using ninja.
+$(shell echo -n $(BUILD_NUMBER) > $(OUT_DIR)/build_number.txt)
+BUILD_NUMBER_FROM_FILE := $$(cat $(OUT_DIR)/build_number.txt)
+
 # CTS-specific config.
 -include cts/build/config.mk