diff --git a/prebuilder.cabal b/prebuilder.cabal
index d59137a7..e763d14f 100644
--- a/prebuilder.cabal
+++ b/prebuilder.cabal
@@ -39,5 +39,6 @@ executable prebuilder
     Rules.Lua
     Rules.Marisa
     Rules.OpenCC
+    Rules.RustToolchain
     Rules.YAMLCpp
     Rules.ZSTD
diff --git a/src/Base.hs b/src/Base.hs
index d4a8e2bc..a36e0659 100644
--- a/src/Base.hs
+++ b/src/Base.hs
@@ -110,6 +110,7 @@ data AndroidEnv = AndroidEnv
     ndkRoot :: FilePath,
     sdkCMakeVersion :: String,
     platform :: Int,
+    rustVersion :: String,
     abi :: String
   }
   deriving stock (Eq, Show, Typeable, Generic)
@@ -141,6 +142,7 @@ getAndroidEnv = do
   ndkRoot <- env "ANDROID_NDK_ROOT"
   sdkCMakeVersion <- env "CMAKE_VERSION"
   platform <- read <$> env "ANDROID_PLATFORM"
+  rustVersion <- env "RUST_VERSION"
   abi <- env "ABI"
   pure AndroidEnv {..}
   where
@@ -174,7 +176,7 @@ execute tool =
   cmdArguments
     ( CmdArgument
         [ Right (outputDir </> "host" </> "bin" </> tool),
-          Left (AddEnv "LD_LIBRARY_PATH" (outputDir </> "host"  </> "lib"))
+          Left (AddEnv "LD_LIBRARY_PATH" (outputDir </> "host" </> "lib"))
         ]
     )
 
diff --git a/src/Main.hs b/src/Main.hs
index 5b189b14..57f5db64 100644
--- a/src/Main.hs
+++ b/src/Main.hs
@@ -19,17 +19,18 @@ import Rules.Fcitx5
 import Rules.GLog
 import Rules.LevelDB
 import Rules.LibChewing
-import Rules.LibUV
-import Rules.LibIconv
 import Rules.LibHangul
 import Rules.LibIME
 import Rules.LibIMEJyutping
+import Rules.LibIconv
 import Rules.LibIntlLite
 import Rules.LibRime
 import Rules.LibThai
+import Rules.LibUV
 import Rules.Lua
 import Rules.Marisa
 import Rules.OpenCC
+import Rules.RustToolchain
 import Rules.YAMLCpp
 import Rules.ZSTD
 
@@ -73,6 +74,8 @@ main = do
       libthaiRule
       libiconvRule
       anthyDictRule
+      hostRustToolchainRule
+      androidRustTargetsRule
       isInGitHubActionRule
       getOutputDirRule
       "everything" ~> do
@@ -194,7 +197,13 @@ instance A.ToJSON ToolchainVersions where
 getToolchainVersions :: Action ToolchainVersions
 getToolchainVersions = do
   StdoutTrim prebuilderRev <- cmd "git" "rev-parse" "HEAD"
-  AndroidEnv {sdkCMakeVersion = cmakeVersion, platform = platformVersion, ..} <- getAndroidEnv
+  AndroidEnv
+    { sdkCMakeVersion = cmakeVersion,
+      platform = platformVersion,
+      rustVersion = rustVersion,
+      ..
+    } <-
+    getAndroidEnv
   properties <- readFileLines $ ndkRoot </> "source.properties"
   ndkVersion <- case find ("Pkg.Revision" `isPrefixOf`) properties of
     Just line
@@ -202,5 +211,4 @@ getToolchainVersions = do
           pure $ dropWhileEnd (== ' ') ndkVersion
       | otherwise -> fail "Failed to parse Pkg.Revision"
     Nothing -> fail "Pkg.Revision not found in source.properties"
-  rustVersion <- fromMaybeM (fail "RUST_VERSION not set") (getEnv "RUST_VERSION")
   pure ToolchainVersions {..}
diff --git a/src/Rules/LibChewing.hs b/src/Rules/LibChewing.hs
index cb206bb5..33078e64 100644
--- a/src/Rules/LibChewing.hs
+++ b/src/Rules/LibChewing.hs
@@ -23,21 +23,10 @@ libchewingRule = do
     useCMake $
       (cmakeBuilder "libchewing")
         { preBuild = BuildAction $ \_ src -> do
-            -- install rust toolchain
-            cmd_ Shell "rustup toolchain install $RUST_VERSION"
             -- CMakeLists.txt changed in last build
             cmd_ (Cwd src) Shell "git checkout ."
             -- disable data/doc, remove absolute path, optimize library size
             cmd_ (Cwd src) "git apply ../patches/libchewing.patch",
-          preBuildEachABI = BuildActionABI $ \_ env -> do
-            -- install rust target for this abi
-            let targetName = case (buildEnvABI env) of
-                  "armeabi-v7a" -> "armv7-linux-androideabi"
-                  "arm64-v8a"   -> "aarch64-linux-android"
-                  "x86"         -> "i686-linux-android"
-                  "x86_64"      -> "x86_64-linux-android"
-                  _             -> fail "Unknown Android ABI"
-            cmd_ "rustup" "target" "add" targetName,
           cmakeFlags =
             const 
               [ "-DBUILD_SHARED_LIBS=OFF",
@@ -49,8 +38,7 @@ libchewingRule = do
         }
 
   "chewing-dict" ~> do
-    -- install rust
-    cmd_ Shell "rustup toolchain install $RUST_VERSION"
+    need ["host-rust-toolchain"]
     let libchewingBuildHost = outputDir </> "libchewing-build-host"
         dictSrcDir = libchewingBuildHost </> "data"
     cmd_ (Cwd libchewingSrc) Shell "git checkout ."
@@ -79,5 +67,5 @@ libchewingRule = do
     copyFile' (dictSrcDir </> "misc" </> "symbols.dat") (dictOutputDir </> "symbols.dat")
 
   "libchewing" ~> do
-    need ["chewing-dict"]
+    need ["chewing-dict", "android-rust-targets"]
     buildWithAndroidEnv buildLibchewing LibChewing
diff --git a/src/Rules/RustToolchain.hs b/src/Rules/RustToolchain.hs
new file mode 100644
index 00000000..c268513a
--- /dev/null
+++ b/src/Rules/RustToolchain.hs
@@ -0,0 +1,27 @@
+module Rules.RustToolchain
+  ( hostRustToolchainRule,
+    androidRustTargetsRule,
+  )
+where
+
+import Base
+
+hostRustToolchainRule :: Rules ()
+hostRustToolchainRule = do
+  "host-rust-toolchain" ~> do
+    androidEnv <- getAndroidEnv
+    cmd_ "rustup" "toolchain" "install" (rustVersion androidEnv)
+
+androidRustTargetsRule :: Rules ()
+androidRustTargetsRule = do
+  "android-rust-targets" ~> do
+    need ["host-rust-toolchain"]
+    androidEnv <- getAndroidEnv
+    forM_ (getABIList androidEnv) $ \a -> do
+      let target = case a of
+            "armeabi-v7a" -> "armv7-linux-androideabi"
+            "arm64-v8a" -> "aarch64-linux-android"
+            "x86_64" -> "x86_64-linux-android"
+            "x86" -> "i686-linux-android"
+            _ -> error $ "Unknown Android ABI: " <> a
+      cmd_ "rustup" "target" "add" target