diff --git a/build/tasks/kernel.mk b/build/tasks/kernel.mk
index f00069f..6ff7b3c 100644
--- a/build/tasks/kernel.mk
+++ b/build/tasks/kernel.mk
@@ -243,12 +243,12 @@
 ifeq ($(TARGET_KERNEL_CLANG_COMPILE),true)
     ifneq ($(TARGET_KERNEL_CLANG_VERSION),)
         # Find the clang-* directory containing the specified version
-        KERNEL_CLANG_VERSION := $(shell find $(ANDROID_BUILD_TOP)/prebuilts/clang/host/$(HOST_OS)-x86/ -name AndroidVersion.txt -exec grep -l $(TARGET_KERNEL_CLANG_VERSION) "{}" \; | sed -e 's|/AndroidVersion.txt$$||g;s|^.*/||g')
+        KERNEL_CLANG_VERSION := $(shell find ./prebuilts/clang/host/$(HOST_OS)-x86/ -name AndroidVersion.txt -exec grep -l $(TARGET_KERNEL_CLANG_VERSION) "{}" \; | sed -e 's|/AndroidVersion.txt$$||g;s|^.*/||g')
     else
         # Only set the latest version of clang if TARGET_KERNEL_CLANG_VERSION hasn't been set by the device config
-        KERNEL_CLANG_VERSION := $(shell ls -d $(ANDROID_BUILD_TOP)/prebuilts/clang/host/$(HOST_OS)-x86/clang-* | xargs -n 1 basename | tail -1)
+        KERNEL_CLANG_VERSION := $(shell ls -d ./prebuilts/clang/host/$(HOST_OS)-x86/clang-* | xargs -n 1 basename | tail -1)
     endif
-    TARGET_KERNEL_CLANG_PATH ?= $(ANDROID_BUILD_TOP)/prebuilts/clang/host/$(HOST_OS)-x86/$(KERNEL_CLANG_VERSION)/bin
+    TARGET_KERNEL_CLANG_PATH ?= ./prebuilts/clang/host/$(HOST_OS)-x86/$(KERNEL_CLANG_VERSION)/bin
     ifeq ($(KERNEL_ARCH),arm64)
         KERNEL_CLANG_TRIPLE ?= CLANG_TRIPLE=aarch64-linux-gnu-
     else ifeq ($(KERNEL_ARCH),arm)
@@ -263,7 +263,7 @@
     ccache := $(shell which ccache)
 
     ifeq ($(ccache),)
-        ccache := $(ANDROID_BUILD_TOP)/prebuilts/misc/$(HOST_PREBUILT_TAG)/ccache/ccache
+        ccache := ./prebuilts/misc/$(HOST_PREBUILT_TAG)/ccache/ccache
         # Check that the executable is here.
         ccache := $(strip $(wildcard $(ccache)))
     endif
@@ -280,7 +280,7 @@
 ccache =
 
 ifeq ($(HOST_OS),darwin)
-  MAKE_FLAGS += C_INCLUDE_PATH=$(ANDROID_BUILD_TOP)/external/elfutils/libelf:/usr/local/opt/openssl/include
+  MAKE_FLAGS += C_INCLUDE_PATH=./external/elfutils/libelf:/usr/local/opt/openssl/include
   MAKE_FLAGS += LIBRARY_PATH=/usr/local/opt/openssl/lib
 endif
 
diff --git a/build/tools/roomservice.py b/build/tools/roomservice.py
index 89efcba..84c67e8 100755
--- a/build/tools/roomservice.py
+++ b/build/tools/roomservice.py
@@ -38,7 +38,7 @@
 # set this to the default remote to use in repo
 default_rem = "omnirom"
 # set this to the default revision to use (branch/tag name)
-default_rev = "android-8.1"
+default_rev = "android-9.0"
 # set this to the remote that you use for projects from your team repos
 # example fetch="https://github.com/omnirom"
 default_team_rem = "omnirom"
diff --git a/google/themes/AccentBlueMonday/Android.mk b/google/themes/AccentBlueMonday/Android.mk
index 0054be7..17bfe4c 100644
--- a/google/themes/AccentBlueMonday/Android.mk
+++ b/google/themes/AccentBlueMonday/Android.mk
@@ -5,6 +5,7 @@
 LOCAL_RRO_THEME := AccentBlueMonday
 LOCAL_CERTIFICATE := platform
 LOCAL_MODULE_TAGS := optional
+LOCAL_SDK_VERSION := 28
 LOCAL_SRC_FILES := $(call all-subdir-java-files)
 LOCAL_RESOURCE_DIR := $(LOCAL_PATH)/res
 
diff --git a/google/themes/AccentDeadRed/Android.mk b/google/themes/AccentDeadRed/Android.mk
index cf8186c..6631fbf 100644
--- a/google/themes/AccentDeadRed/Android.mk
+++ b/google/themes/AccentDeadRed/Android.mk
@@ -5,6 +5,7 @@
 LOCAL_RRO_THEME := AccentDeadRed
 LOCAL_CERTIFICATE := platform
 LOCAL_MODULE_TAGS := optional
+LOCAL_SDK_VERSION := 28
 LOCAL_SRC_FILES := $(call all-subdir-java-files)
 LOCAL_RESOURCE_DIR := $(LOCAL_PATH)/res
 
diff --git a/google/themes/AccentDeepOrange/Android.mk b/google/themes/AccentDeepOrange/Android.mk
index 4812013..bfd7d86 100644
--- a/google/themes/AccentDeepOrange/Android.mk
+++ b/google/themes/AccentDeepOrange/Android.mk
@@ -5,6 +5,7 @@
 LOCAL_RRO_THEME := AccentDeepOrange
 LOCAL_CERTIFICATE := platform
 LOCAL_MODULE_TAGS := optional
+LOCAL_SDK_VERSION := 28
 LOCAL_SRC_FILES := $(call all-subdir-java-files)
 LOCAL_RESOURCE_DIR := $(LOCAL_PATH)/res
 
diff --git a/google/themes/AccentDeepPurple/Android.mk b/google/themes/AccentDeepPurple/Android.mk
index 9bebb2d..7a24302 100644
--- a/google/themes/AccentDeepPurple/Android.mk
+++ b/google/themes/AccentDeepPurple/Android.mk
@@ -5,6 +5,7 @@
 LOCAL_RRO_THEME := AccentDeepPurple
 LOCAL_CERTIFICATE := platform
 LOCAL_MODULE_TAGS := optional
+LOCAL_SDK_VERSION := 28
 LOCAL_SRC_FILES := $(call all-subdir-java-files)
 LOCAL_RESOURCE_DIR := $(LOCAL_PATH)/res
 
diff --git a/google/themes/AccentFromHell/Android.mk b/google/themes/AccentFromHell/Android.mk
index da8412a..78dd8aa 100644
--- a/google/themes/AccentFromHell/Android.mk
+++ b/google/themes/AccentFromHell/Android.mk
@@ -5,6 +5,7 @@
 LOCAL_RRO_THEME := AccentFromHell
 LOCAL_CERTIFICATE := platform
 LOCAL_MODULE_TAGS := optional
+LOCAL_SDK_VERSION := 28
 LOCAL_SRC_FILES := $(call all-subdir-java-files)
 LOCAL_RESOURCE_DIR := $(LOCAL_PATH)/res
 
diff --git a/google/themes/AccentGoldenShower/Android.mk b/google/themes/AccentGoldenShower/Android.mk
index 52cbc49..bac13c5 100644
--- a/google/themes/AccentGoldenShower/Android.mk
+++ b/google/themes/AccentGoldenShower/Android.mk
@@ -5,6 +5,7 @@
 LOCAL_RRO_THEME := AccnetGoldenShower
 LOCAL_CERTIFICATE := platform
 LOCAL_MODULE_TAGS := optional
+LOCAL_SDK_VERSION := 28
 LOCAL_SRC_FILES := $(call all-subdir-java-files)
 LOCAL_RESOURCE_DIR := $(LOCAL_PATH)/res
 
diff --git a/google/themes/AccentOmni/Android.mk b/google/themes/AccentOmni/Android.mk
index 059d9c1..6764eeb 100644
--- a/google/themes/AccentOmni/Android.mk
+++ b/google/themes/AccentOmni/Android.mk
@@ -5,6 +5,7 @@
 LOCAL_RRO_THEME := AccentOmni
 LOCAL_CERTIFICATE := platform
 LOCAL_MODULE_TAGS := optional
+LOCAL_SDK_VERSION := 28
 LOCAL_SRC_FILES := $(call all-subdir-java-files)
 LOCAL_RESOURCE_DIR := $(LOCAL_PATH)/res
 
diff --git a/google/themes/AccentPixel/Android.mk b/google/themes/AccentPixel/Android.mk
index 22c521c..44f046b 100644
--- a/google/themes/AccentPixel/Android.mk
+++ b/google/themes/AccentPixel/Android.mk
@@ -5,6 +5,7 @@
 LOCAL_RRO_THEME := AccentPixel
 LOCAL_CERTIFICATE := platform
 LOCAL_MODULE_TAGS := optional
+LOCAL_SDK_VERSION := 28
 LOCAL_SRC_FILES := $(call all-subdir-java-files)
 LOCAL_RESOURCE_DIR := $(LOCAL_PATH)/res
 
diff --git a/google/themes/AccentRottenOrange/Android.mk b/google/themes/AccentRottenOrange/Android.mk
index 6004cce..e929d22 100644
--- a/google/themes/AccentRottenOrange/Android.mk
+++ b/google/themes/AccentRottenOrange/Android.mk
@@ -5,6 +5,7 @@
 LOCAL_RRO_THEME := AccentRottenOrange
 LOCAL_CERTIFICATE := platform
 LOCAL_MODULE_TAGS := optional
+LOCAL_SDK_VERSION := 28
 LOCAL_SRC_FILES := $(call all-subdir-java-files)
 LOCAL_RESOURCE_DIR := $(LOCAL_PATH)/res
 
diff --git a/google/themes/AccentSluttyPink/Android.mk b/google/themes/AccentSluttyPink/Android.mk
index 0930ef7..5ea096a 100644
--- a/google/themes/AccentSluttyPink/Android.mk
+++ b/google/themes/AccentSluttyPink/Android.mk
@@ -5,6 +5,7 @@
 LOCAL_RRO_THEME := AccentSluttyPink
 LOCAL_CERTIFICATE := platform
 LOCAL_MODULE_TAGS := optional
+LOCAL_SDK_VERSION := 28
 LOCAL_SRC_FILES := $(call all-subdir-java-files)
 LOCAL_RESOURCE_DIR := $(LOCAL_PATH)/res
 
diff --git a/google/themes/AccentSmokingGreen/Android.mk b/google/themes/AccentSmokingGreen/Android.mk
index 05bfbff..a01a363 100644
--- a/google/themes/AccentSmokingGreen/Android.mk
+++ b/google/themes/AccentSmokingGreen/Android.mk
@@ -5,6 +5,7 @@
 LOCAL_RRO_THEME := AccentSmokingGreen
 LOCAL_CERTIFICATE := platform
 LOCAL_MODULE_TAGS := optional
+LOCAL_SDK_VERSION := 28
 LOCAL_SRC_FILES := $(call all-subdir-java-files)
 LOCAL_RESOURCE_DIR := $(LOCAL_PATH)/res
 
diff --git a/google/themes/AccentTeal/Android.mk b/google/themes/AccentTeal/Android.mk
index 9a624fb..e107415 100644
--- a/google/themes/AccentTeal/Android.mk
+++ b/google/themes/AccentTeal/Android.mk
@@ -5,6 +5,7 @@
 LOCAL_RRO_THEME := AccentTeal
 LOCAL_CERTIFICATE := platform
 LOCAL_MODULE_TAGS := optional
+LOCAL_SDK_VERSION := 28
 LOCAL_SRC_FILES := $(call all-subdir-java-files)
 LOCAL_RESOURCE_DIR := $(LOCAL_PATH)/res
 
diff --git a/google/themes/AccentWhite/Android.mk b/google/themes/AccentWhite/Android.mk
index e1462c1..6fdd2ce 100644
--- a/google/themes/AccentWhite/Android.mk
+++ b/google/themes/AccentWhite/Android.mk
@@ -5,6 +5,7 @@
 LOCAL_RRO_THEME := AccentWhite
 LOCAL_CERTIFICATE := platform
 LOCAL_MODULE_TAGS := optional
+LOCAL_SDK_VERSION := 28
 LOCAL_SRC_FILES := $(call all-subdir-java-files)
 LOCAL_RESOURCE_DIR := $(LOCAL_PATH)/res
 
diff --git a/google/themes/Bl4ckAndYell0/Android.mk b/google/themes/Bl4ckAndYell0/Android.mk
index c3a827c..2bbab0a 100644
--- a/google/themes/Bl4ckAndYell0/Android.mk
+++ b/google/themes/Bl4ckAndYell0/Android.mk
@@ -5,6 +5,7 @@
 LOCAL_RRO_THEME := Bl4ckAndYell0Theme
 LOCAL_CERTIFICATE := platform
 LOCAL_MODULE_TAGS := optional
+LOCAL_SDK_VERSION := 28
 LOCAL_SRC_FILES := $(call all-subdir-java-files)
 LOCAL_RESOURCE_DIR := $(LOCAL_PATH)/res
 
diff --git a/google/themes/DarknessMeister/Android.mk b/google/themes/DarknessMeister/Android.mk
index f46f5d1..7a76473 100644
--- a/google/themes/DarknessMeister/Android.mk
+++ b/google/themes/DarknessMeister/Android.mk
@@ -5,6 +5,7 @@
 LOCAL_RRO_THEME := DarknessMeisterTheme
 LOCAL_CERTIFICATE := platform
 LOCAL_MODULE_TAGS := optional
+LOCAL_SDK_VERSION := 28
 LOCAL_SRC_FILES := $(call all-subdir-java-files)
 LOCAL_RESOURCE_DIR := $(LOCAL_PATH)/res
 
diff --git a/google/themes/FromHell/Android.mk b/google/themes/FromHell/Android.mk
index 806ce1a..0b814b2 100644
--- a/google/themes/FromHell/Android.mk
+++ b/google/themes/FromHell/Android.mk
@@ -5,6 +5,7 @@
 LOCAL_RRO_THEME := FromHellTheme
 LOCAL_CERTIFICATE := platform
 LOCAL_MODULE_TAGS := optional
+LOCAL_SDK_VERSION := 28
 LOCAL_SRC_FILES := $(call all-subdir-java-files)
 LOCAL_RESOURCE_DIR := $(LOCAL_PATH)/res
 
diff --git a/google/themes/GboardOmniTheme/Android.mk b/google/themes/GboardOmniTheme/Android.mk
index 5fcb793..4e60248 100644
--- a/google/themes/GboardOmniTheme/Android.mk
+++ b/google/themes/GboardOmniTheme/Android.mk
@@ -5,6 +5,7 @@
 LOCAL_RRO_THEME := GboardOmniTheme
 LOCAL_CERTIFICATE := platform
 LOCAL_MODULE_TAGS := optional
+LOCAL_SDK_VERSION := 28
 LOCAL_SRC_FILES := $(call all-subdir-java-files)
 LOCAL_RESOURCE_DIR := $(LOCAL_PATH)/res
 
diff --git a/google/themes/NotificationsDark/Android.mk b/google/themes/NotificationsDark/Android.mk
index e6b089a..c2995c8 100644
--- a/google/themes/NotificationsDark/Android.mk
+++ b/google/themes/NotificationsDark/Android.mk
@@ -5,6 +5,7 @@
 LOCAL_RRO_THEME := NotificationsDark
 LOCAL_CERTIFICATE := platform
 LOCAL_MODULE_TAGS := optional
+LOCAL_SDK_VERSION := 28
 LOCAL_SRC_FILES := $(call all-subdir-java-files)
 LOCAL_RESOURCE_DIR := $(LOCAL_PATH)/res
 
diff --git a/google/themes/NotificationsLight/Android.mk b/google/themes/NotificationsLight/Android.mk
index 24f3db4..efc7840 100644
--- a/google/themes/NotificationsLight/Android.mk
+++ b/google/themes/NotificationsLight/Android.mk
@@ -5,6 +5,7 @@
 LOCAL_RRO_THEME := NotificationsLight
 LOCAL_CERTIFICATE := platform
 LOCAL_MODULE_TAGS := optional
+LOCAL_SDK_VERSION := 28
 LOCAL_SRC_FILES := $(call all-subdir-java-files)
 LOCAL_RESOURCE_DIR := $(LOCAL_PATH)/res
 
diff --git a/google/themes/NotificationsPrimary/Android.mk b/google/themes/NotificationsPrimary/Android.mk
index d5ce1fe..dcced9e 100644
--- a/google/themes/NotificationsPrimary/Android.mk
+++ b/google/themes/NotificationsPrimary/Android.mk
@@ -5,6 +5,7 @@
 LOCAL_RRO_THEME := NotificationsPrimary
 LOCAL_CERTIFICATE := platform
 LOCAL_MODULE_TAGS := optional
+LOCAL_SDK_VERSION := 28
 LOCAL_SRC_FILES := $(call all-subdir-java-files)
 LOCAL_RESOURCE_DIR := $(LOCAL_PATH)/res
 
diff --git a/google/themes/OmniTheme/Android.mk b/google/themes/OmniTheme/Android.mk
index 55cbf67..4aeda03 100644
--- a/google/themes/OmniTheme/Android.mk
+++ b/google/themes/OmniTheme/Android.mk
@@ -5,6 +5,7 @@
 LOCAL_RRO_THEME := OmniTheme
 LOCAL_CERTIFICATE := platform
 LOCAL_MODULE_TAGS := optional
+LOCAL_SDK_VERSION := 28
 LOCAL_SRC_FILES := $(call all-subdir-java-files)
 LOCAL_RESOURCE_DIR := $(LOCAL_PATH)/res
 
diff --git a/google/themes/Pixel/Android.mk b/google/themes/Pixel/Android.mk
index 37bd941..741798f 100644
--- a/google/themes/Pixel/Android.mk
+++ b/google/themes/Pixel/Android.mk
@@ -5,6 +5,7 @@
 LOCAL_RRO_THEME := PixelTheme
 LOCAL_CERTIFICATE := platform
 LOCAL_MODULE_TAGS := optional
+LOCAL_SDK_VERSION := 28
 LOCAL_SRC_FILES := $(call all-subdir-java-files)
 LOCAL_RESOURCE_DIR := $(LOCAL_PATH)/res
 
diff --git a/google/themes/PrimaryAlmostBlack/Android.mk b/google/themes/PrimaryAlmostBlack/Android.mk
index a036964..ceceec3 100644
--- a/google/themes/PrimaryAlmostBlack/Android.mk
+++ b/google/themes/PrimaryAlmostBlack/Android.mk
@@ -5,6 +5,7 @@
 LOCAL_RRO_THEME := PrimaryAlmostBlack
 LOCAL_CERTIFICATE := platform
 LOCAL_MODULE_TAGS := optional
+LOCAL_SDK_VERSION := 28
 LOCAL_SRC_FILES := $(call all-subdir-java-files)
 LOCAL_RESOURCE_DIR := $(LOCAL_PATH)/res
 
diff --git a/google/themes/PrimaryBlack/Android.mk b/google/themes/PrimaryBlack/Android.mk
index 9ea3767..a00b3c9 100644
--- a/google/themes/PrimaryBlack/Android.mk
+++ b/google/themes/PrimaryBlack/Android.mk
@@ -5,6 +5,7 @@
 LOCAL_RRO_THEME := PrimaryBlack
 LOCAL_CERTIFICATE := platform
 LOCAL_MODULE_TAGS := optional
+LOCAL_SDK_VERSION := 28
 LOCAL_SRC_FILES := $(call all-subdir-java-files)
 LOCAL_RESOURCE_DIR := $(LOCAL_PATH)/res
 
diff --git a/google/themes/PrimaryColdWhite/Android.mk b/google/themes/PrimaryColdWhite/Android.mk
index 9ac1a8d..952177c 100644
--- a/google/themes/PrimaryColdWhite/Android.mk
+++ b/google/themes/PrimaryColdWhite/Android.mk
@@ -5,6 +5,7 @@
 LOCAL_RRO_THEME := PrimaryColdWhite
 LOCAL_CERTIFICATE := platform
 LOCAL_MODULE_TAGS := optional
+LOCAL_SDK_VERSION := 28
 LOCAL_SRC_FILES := $(call all-subdir-java-files)
 LOCAL_RESOURCE_DIR := $(LOCAL_PATH)/res
 
diff --git a/google/themes/PrimaryDarkBlue/Android.mk b/google/themes/PrimaryDarkBlue/Android.mk
index 6642c36..0b566e1 100644
--- a/google/themes/PrimaryDarkBlue/Android.mk
+++ b/google/themes/PrimaryDarkBlue/Android.mk
@@ -5,6 +5,7 @@
 LOCAL_RRO_THEME := PrimaryDarkBlue
 LOCAL_CERTIFICATE := platform
 LOCAL_MODULE_TAGS := optional
+LOCAL_SDK_VERSION := 28
 LOCAL_SRC_FILES := $(call all-subdir-java-files)
 LOCAL_RESOURCE_DIR := $(LOCAL_PATH)/res
 
diff --git a/google/themes/PrimaryOmni/Android.mk b/google/themes/PrimaryOmni/Android.mk
index 4ebf813..f98ae60 100644
--- a/google/themes/PrimaryOmni/Android.mk
+++ b/google/themes/PrimaryOmni/Android.mk
@@ -5,6 +5,7 @@
 LOCAL_RRO_THEME := PrimaryOmni
 LOCAL_CERTIFICATE := platform
 LOCAL_MODULE_TAGS := optional
+LOCAL_SDK_VERSION := 28
 LOCAL_SRC_FILES := $(call all-subdir-java-files)
 LOCAL_RESOURCE_DIR := $(LOCAL_PATH)/res
 
diff --git a/google/themes/PrimaryWarmWhite/Android.mk b/google/themes/PrimaryWarmWhite/Android.mk
index 39b0fa7..7c5f0a1 100644
--- a/google/themes/PrimaryWarmWhite/Android.mk
+++ b/google/themes/PrimaryWarmWhite/Android.mk
@@ -5,6 +5,7 @@
 LOCAL_RRO_THEME := PrimaryWarmWhite
 LOCAL_CERTIFICATE := platform
 LOCAL_MODULE_TAGS := optional
+LOCAL_SDK_VERSION := 28
 LOCAL_SRC_FILES := $(call all-subdir-java-files)
 LOCAL_RESOURCE_DIR := $(LOCAL_PATH)/res
 
diff --git a/google/themes/PrimaryWhite/Android.mk b/google/themes/PrimaryWhite/Android.mk
index 0b46670..4bc1d5b 100644
--- a/google/themes/PrimaryWhite/Android.mk
+++ b/google/themes/PrimaryWhite/Android.mk
@@ -5,6 +5,7 @@
 LOCAL_RRO_THEME := PrimaryWhite
 LOCAL_CERTIFICATE := platform
 LOCAL_MODULE_TAGS := optional
+LOCAL_SDK_VERSION := 28
 LOCAL_SRC_FILES := $(call all-subdir-java-files)
 LOCAL_RESOURCE_DIR := $(LOCAL_PATH)/res
 
diff --git a/google/themes/SluttyPink/Android.mk b/google/themes/SluttyPink/Android.mk
index 7f59e5b..fc5754d 100644
--- a/google/themes/SluttyPink/Android.mk
+++ b/google/themes/SluttyPink/Android.mk
@@ -5,6 +5,7 @@
 LOCAL_RRO_THEME := SluttyPinkTheme
 LOCAL_CERTIFICATE := platform
 LOCAL_MODULE_TAGS := optional
+LOCAL_SDK_VERSION := 28
 LOCAL_SRC_FILES := $(call all-subdir-java-files)
 LOCAL_RESOURCE_DIR := $(LOCAL_PATH)/res
 
diff --git a/google/themes/SmokedGreen/Android.mk b/google/themes/SmokedGreen/Android.mk
index 2e75680..acd63dd 100644
--- a/google/themes/SmokedGreen/Android.mk
+++ b/google/themes/SmokedGreen/Android.mk
@@ -5,6 +5,7 @@
 LOCAL_RRO_THEME := SmokedGreenTheme
 LOCAL_CERTIFICATE := platform
 LOCAL_MODULE_TAGS := optional
+LOCAL_SDK_VERSION := 28
 LOCAL_SRC_FILES := $(call all-subdir-java-files)
 LOCAL_RESOURCE_DIR := $(LOCAL_PATH)/res
 
diff --git a/google/themes/ZeroZero/Android.mk b/google/themes/ZeroZero/Android.mk
index 8c22dcc..a6e91d0 100644
--- a/google/themes/ZeroZero/Android.mk
+++ b/google/themes/ZeroZero/Android.mk
@@ -5,6 +5,7 @@
 LOCAL_RRO_THEME := ZeroZeroTheme
 LOCAL_CERTIFICATE := platform
 LOCAL_MODULE_TAGS := optional
+LOCAL_SDK_VERSION := 28
 LOCAL_SRC_FILES := $(call all-subdir-java-files)
 LOCAL_RESOURCE_DIR := $(LOCAL_PATH)/res
 
diff --git a/overlay/common/frameworks/base/core/res/res/values/config.xml b/overlay/common/frameworks/base/core/res/res/values/config.xml
index d412e76..a6084e6 100644
--- a/overlay/common/frameworks/base/core/res/res/values/config.xml
+++ b/overlay/common/frameworks/base/core/res/res/values/config.xml
@@ -25,13 +25,13 @@
 
     <string-array translatable="false" name="config_defaultPinnerServiceFiles">
         <item>"/system/framework/arm64/boot-framework.oat"</item>
-        <item>"/system/framework/arm64/boot-framework.vdex"</item>
+        <item>"/system/framework/boot-framework.vdex"</item>
         <item>"/system/framework/oat/arm64/services.odex"</item>
         <item>"/system/framework/oat/arm64/services.vdex"</item>
         <item>"/system/framework/arm64/boot.oat"</item>
-        <item>"/system/framework/arm64/boot.vdex"</item>
+        <item>"/system/framework/boot.vdex"</item>
         <item>"/system/framework/arm64/boot-core-libart.oat"</item>
-        <item>"/system/framework/arm64/boot-core-libart.vdex"</item>
+        <item>"/system/framework/boot-core-libart.vdex"</item>
     </string-array>
 
     <!-- Controls the WiFi wakeup feature.
diff --git a/prebuilt/bin/backuptool.sh b/prebuilt/bin/backuptool.sh
index a20454f..8b26032 100755
--- a/prebuilt/bin/backuptool.sh
+++ b/prebuilt/bin/backuptool.sh
@@ -5,7 +5,7 @@
 
 export C=/tmp/backupdir
 export S=/system
-export V=8.1
+export V=9.0
 
 export ADDOND_VERSION=1
 
diff --git a/prebuilt/common/bin/backuptool_ab.functions b/prebuilt/common/bin/backuptool_ab.functions
index 5a9ce56..f227ec1 100644
--- a/prebuilt/common/bin/backuptool_ab.functions
+++ b/prebuilt/common/bin/backuptool_ab.functions
@@ -5,7 +5,7 @@
 
 export S=/system
 export C=/postinstall/tmp/backupdir
-export V=8.1
+export V=9.0
 export backuptool_ab=true
 
 copy_file() {
diff --git a/prebuilt/common/bin/backuptool_ab.sh b/prebuilt/common/bin/backuptool_ab.sh
index 8c5e7f6..6981ba8 100755
--- a/prebuilt/common/bin/backuptool_ab.sh
+++ b/prebuilt/common/bin/backuptool_ab.sh
@@ -5,7 +5,7 @@
 
 export S=/system
 export C=/postinstall/tmp/backupdir
-export V=8.1
+export V=9.0
 
 export ADDOND_VERSION=2
 
diff --git a/utils/aosp-push-merge.sh b/utils/aosp-push-merge.sh
index b41177b..d6e7fb8 100755
--- a/utils/aosp-push-merge.sh
+++ b/utils/aosp-push-merge.sh
@@ -19,7 +19,7 @@
 
 url="gerrit.omnirom.org"
 port="29418"
-branch="android-8.1"
+branch="android-9.0"
 
 cd ../../../
 
diff --git a/utils/fork_aosp.sh b/utils/fork_aosp.sh
index fc06f2b..b3b9dee 100755
--- a/utils/fork_aosp.sh
+++ b/utils/fork_aosp.sh
@@ -4,8 +4,8 @@
 
 # Configuration
 PREFIX=android_
-BRANCH=android-8.1
-SOURCE=android-8.1.0_r<INSERT_CORRECT_TAG>
+BRANCH=android-9.0
+SOURCE=android-9.0.0_r<INSERT_CORRECT_TAG>
 USERNAME=<INSERT USER>
 MANIFEST=android/default.xml
 REMOVE=android/remove.xml