diff --git a/libs/build_deps.sh b/libs/build_deps.sh
index fdb24d5..9840d3f 100755
--- a/libs/build_deps.sh
+++ b/libs/build_deps.sh
@@ -3,10 +3,25 @@ set -euo pipefail
 
 # Builds shadowhook as a static library for Android arm64.
 # Produces: libs/libshadowhook.a and libs/libshadowhook_nothing.so
+#
+# Skips the build entirely if both outputs already exist. Set FORCE_REBUILD=1
+# to rebuild anyway (e.g. after changing CFLAGS, the toolchain, or the
+# shadowhook sources themselves).
 
 SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
 PROJECT_DIR="$(dirname "$SCRIPT_DIR")"
 BUILD_DIR="$PROJECT_DIR/build/deps"
+
+OUT_DIR="$SCRIPT_DIR"
+SH="$SCRIPT_DIR/shadowhook/shadowhook/src/main/cpp"
+
+if [ "${FORCE_REBUILD:-0}" != "1" ] \
+    && [ -f "$OUT_DIR/libshadowhook.a" ] \
+    && [ -f "$OUT_DIR/libshadowhook_nothing.so" ]; then
+    echo "=== shadowhook already built, skipping (FORCE_REBUILD=1 to rebuild) ==="
+    exit 0
+fi
+
 mkdir -p "$BUILD_DIR"
 
 # --- Auto-detect Android NDK (same logic as build.sh) ---
@@ -47,81 +62,67 @@ TOOLCHAIN_DIR="$(dirname "$CC")"
 AR="$TOOLCHAIN_DIR/llvm-ar"
 CFLAGS="-O2 -ffunction-sections -fdata-sections -fPIC -DANDROID -Wall -Wextra -Wno-unused-parameter -Wno-unused-function"
 
-OUT_DIR="$SCRIPT_DIR"
+SH_SRCS=(
+    "$SH/sh_elf.c"
+    "$SH/sh_enter.c"
+    "$SH/sh_hub.c"
+    "$SH/sh_island.c"
+    "$SH/sh_linker.c"
+    "$SH/sh_recorder.c"
+    "$SH/sh_safe.c"
+    "$SH/sh_switch.c"
+    "$SH/sh_task.c"
+    "$SH/sh_xdl.c"
+    "$SH/shadowhook.c"
+    "$SH/arch/arm64/sh_a64.c"
+    "$SH/arch/arm64/sh_inst.c"
+    "$SH/arch/arm64/sh_glue.S"
+    "$SH/common/bytesig.c"
+    "$SH/common/sh_errno.c"
+    "$SH/common/sh_log.c"
+    "$SH/common/sh_ref.c"
+    "$SH/common/sh_trampo.c"
+    "$SH/common/sh_util.c"
+    "$SH/third_party/xdl/xdl.c"
+    "$SH/third_party/xdl/xdl_iterate.c"
+    "$SH/third_party/xdl/xdl_linker.c"
+    "$SH/third_party/xdl/xdl_lzma.c"
+    "$SH/third_party/xdl/xdl_util.c"
+)
+
+SH_INCLUDES=(
+    "-I$SH"
+    "-I$SH/include"
+    "-I$SH/arch/arm64"
+    "-I$SH/common"
+    "-I$SH/third_party/xdl"
+    "-I$SH/third_party/bsd"
+    "-I$SH/third_party/lss"
+)
+
+NOTHING_SRC="$SH/nothing/sh_nothing.c"
 
 echo "=== Building shadowhook (arm64-v8a) ==="
 
-SH="$SCRIPT_DIR/shadowhook/shadowhook/src/main/cpp"
-
-SH_SRCS="
-$SH/sh_elf.c
-$SH/sh_enter.c
-$SH/sh_hub.c
-$SH/sh_island.c
-$SH/sh_linker.c
-$SH/sh_recorder.c
-$SH/sh_safe.c
-$SH/sh_switch.c
-$SH/sh_task.c
-$SH/sh_xdl.c
-$SH/shadowhook.c
-$SH/arch/arm64/sh_a64.c
-$SH/arch/arm64/sh_inst.c
-$SH/arch/arm64/sh_glue.S
-$SH/common/bytesig.c
-$SH/common/sh_errno.c
-$SH/common/sh_log.c
-$SH/common/sh_ref.c
-$SH/common/sh_trampo.c
-$SH/common/sh_util.c
-$SH/third_party/xdl/xdl.c
-$SH/third_party/xdl/xdl_iterate.c
-$SH/third_party/xdl/xdl_linker.c
-$SH/third_party/xdl/xdl_lzma.c
-$SH/third_party/xdl/xdl_util.c
-"
-
-SH_INCLUDES="
--I$SH
--I$SH/include
--I$SH/arch/arm64
--I$SH/common
--I$SH/third_party/xdl
--I$SH/third_party/bsd
--I$SH/third_party/lss
-"
-
-SH_OBJS=""
-for src in $SH_SRCS; do
-    [ -z "$src" ] && continue
-    src=$(echo "$src" | xargs)
+SH_OBJS=()
+for src in "${SH_SRCS[@]}"; do
     if [ ! -f "$src" ]; then
         echo "ERROR: shadowhook source not found: $src"
         exit 1
     fi
 
-    basename=$(echo "$src" | sed "s|$SH/||" | tr '/' '_')
-    obj="$BUILD_DIR/sh_${basename%.c}.o"
-    obj="${obj%.S.o}.o"
+    rel="${src#"$SH"/}"
+    flat="$(echo "$rel" | tr '/' '_')"
+    obj="$BUILD_DIR/sh_${flat%.*}.o"
 
-    if [[ "$src" == *.S ]]; then
-        "$CC" $CFLAGS $SH_INCLUDES -c "$src" -o "$obj"
-    else
-        "$CC" $CFLAGS $SH_INCLUDES -c "$src" -o "$obj"
-    fi
-    SH_OBJS="$SH_OBJS $obj"
+    "$CC" $CFLAGS "${SH_INCLUDES[@]}" -c "$src" -o "$obj"
+    SH_OBJS+=("$obj")
 done
 
-if [ -z "$SH_OBJS" ]; then
-    echo "ERROR: shadowhook produced no object files."
-    exit 1
-fi
-
-"$AR" rcs "$OUT_DIR/libshadowhook.a" $SH_OBJS
+"$AR" rcs "$OUT_DIR/libshadowhook.a" "${SH_OBJS[@]}"
 SH_SIZE=$(wc -c < "$OUT_DIR/libshadowhook.a" 2>/dev/null || echo "unknown")
 echo "  Built $OUT_DIR/libshadowhook.a ($SH_SIZE bytes)"
 
-NOTHING_SRC="$SH/nothing/sh_nothing.c"
 if [ ! -f "$NOTHING_SRC" ]; then
     echo "ERROR: ShadowHook companion source not found: $NOTHING_SRC"
     exit 1
@@ -133,4 +134,4 @@ fi
     -Wl,--strip-all -Wl,--as-needed -Wl,--hash-style=sysv \
     -Wl,--build-id=none \
     -o "$OUT_DIR/libshadowhook_nothing.so" "$NOTHING_SRC"
-echo "  Built $OUT_DIR/libshadowhook_nothing.so"
+echo "  Built $OUT_DIR/libshadowhook_nothing.so"
\ No newline at end of file
diff --git a/script/build.sh b/script/build.sh
index 4d2d022..8e3585c 100755
--- a/script/build.sh
+++ b/script/build.sh
@@ -95,6 +95,7 @@ echo "✅ Qt libraries ready at $QT_LIB_DIR"
 # --- Step 2: Compile native hooking library ---
 echo "[2/2] Compiling $SO_NAME..."
 
+# shellcheck disable=SC2086
 "$CC" -shared -fPIC -O2 -std=c++17 -stdlib=libc++ -fno-exceptions -fno-rtti \
     -DQT_NO_VERSION_TAGGING \
     -o "$BUILD_DIR/$SO_NAME" \
@@ -120,4 +121,4 @@ echo "📍 Library: $BUILD_DIR/$SO_NAME ($(ls -lh "$BUILD_DIR/$SO_NAME" | awk '{
 echo ""
 echo "🚀 To inject into the reMarkable application:"
 echo "   ./script/inject.sh"
-echo ""
+echo ""
\ No newline at end of file
diff --git a/script/inject.sh b/script/inject.sh
index 26c123c..115f381 100755
--- a/script/inject.sh
+++ b/script/inject.sh
@@ -33,6 +33,17 @@ KEYSTORE="$PROJECT_DIR/config/rmhook.keystore"
 KEYSTORE_PASS="rmhook"
 KEY_ALIAS="rmhook"
 
+# --- Portable in-place sed (GNU sed vs BSD/macOS sed take -i differently) ---
+sed_inplace() {
+    if sed --version >/dev/null 2>&1; then
+        # GNU sed
+        sed -i "$@"
+    else
+        # BSD/macOS sed requires an explicit (possibly empty) backup suffix
+        sed -i '' "$@"
+    fi
+}
+
 usage() {
     echo "Usage: $0 [apk_dir]"
     echo ""
@@ -56,6 +67,8 @@ fi
 # Clean and create output directory
 rm -rf "$OUTPUT_DIR"
 mkdir -p "$OUTPUT_DIR"
+rm -rf "$BUILD_DIR/base" "$BUILD_DIR/split_arm64" "$BUILD_DIR/split_xxhdpi"
+rm -f "$BUILD_DIR"/*.apk
 
 # --- Step 1: Decompile and patch base.apk (smali injection only, no resources) ---
 echo "[1/4] Patching base.apk (smali injection)..."
@@ -69,7 +82,7 @@ if [ ! -f "$MAIN_SMALI" ]; then
 fi
 
 # Insert System.loadLibrary("rmhook") at the very start of <clinit>
-sed -i '' '/.method static constructor <clinit>()V/{
+sed_inplace '/.method static constructor <clinit>()V/{
 n
 /.locals/{
 a\
@@ -80,6 +93,12 @@ a\
 }
 }' "$MAIN_SMALI"
 
+if ! grep -q 'invoke-static {v0}, Ljava/lang/System;->loadLibrary' "$MAIN_SMALI"; then
+    echo "❌ Failed to inject loadLibrary(\"rmhook\") into MainActivity.smali"
+    echo "   The <clinit> block's shape may have changed - inspect $MAIN_SMALI manually."
+    exit 1
+fi
+
 echo "✅ Injected System.loadLibrary(\"rmhook\") into MainActivity.<clinit>"
 
 apktool b "$BUILD_DIR/base" -o "$BUILD_DIR/base_patched.apk"
@@ -100,8 +119,8 @@ cp "$LIBS_DIR/libshadowhook_nothing.so" "$BUILD_DIR/split_arm64/lib/arm64-v8a/"
 
 rm -rf "$BUILD_DIR/split_arm64/META-INF"
 
-(cd "$BUILD_DIR/split_arm64" && zip -q -r -0 "$BUILD_DIR/split_arm64_raw.apk" . -x "*.so")
-(cd "$BUILD_DIR/split_arm64" && zip -q -r "$BUILD_DIR/split_arm64_raw.apk" lib/)
+# Store everything uncompressed (-0), including the native libraries.
+(cd "$BUILD_DIR/split_arm64" && zip -q -r -0 "$BUILD_DIR/split_arm64_raw.apk" .)
 
 # --- Step 3: Align APKs ---
 echo "[3/4] Aligning APKs..."
@@ -160,7 +179,8 @@ echo ""
 echo "🚀 To install on your reMarkable:"
 echo "   adb uninstall com.remarkable.mobile"
 echo "   adb install-multiple --no-streaming $OUTPUT_DIR/base.apk $OUTPUT_DIR/split_config.arm64_v8a.apk $OUTPUT_DIR/split_config.xxhdpi.apk"
+echo "   adb push rmhook.conf /sdcard/Android/data/com.remarkable.mobile/files/rmhook.conf"
 echo ""
 echo "🔍 To debug:"
 echo "   adb logcat -s 'RMHook:*'"
-echo ""
+echo ""
\ No newline at end of file