diff --git a/.env.example b/.env.example
index 7aebdae..e76874a 100644
--- a/.env.example
+++ b/.env.example
@@ -31,6 +31,13 @@ MODELS_DIR=./models
 #
 # ACESTEP_API_URL=http://localhost:7860
 
+# ── acestep-cpp source / custom fork ─────────────────────────────────────────
+# Override the repository cloned by build.sh (useful for custom forks):
+# ACESTEP_CPP_REPO=https://github.com/your-fork/acestep.cpp.git
+#
+# Checkout a specific branch or tag after cloning:
+# ACESTEP_CPP_BRANCH=main
+
 # ── Storage ───────────────────────────────────────────────────────────────────
 AUDIO_DIR=./public/audio
 
diff --git a/build.sh b/build.sh
index 26103d0..6edd2b2 100755
--- a/build.sh
+++ b/build.sh
@@ -10,7 +10,8 @@
 #   --rocm         force ROCm/HIP build
 #   --vulkan       force Vulkan build
 #   --cpu          CPU-only build (disable GPU auto-detection)
-#   --repo URL     override the git repository to clone
+#   --repo URL     override the git repository to clone (env: ACESTEP_CPP_REPO)
+#   --branch NAME  checkout a specific branch/tag after cloning (env: ACESTEP_CPP_BRANCH)
 
 set -e
 
@@ -19,6 +20,7 @@ SRC_DIR="${ACESTEP_CPP_SRC:-$DIR/acestep.cpp}"
 BIN_DIR="${ACESTEP_BIN_DIR:-$DIR/bin}"
 BUILD_DIR="$SRC_DIR/build"
 REPO="${ACESTEP_CPP_REPO:-https://github.com/audiohacking/acestep.cpp.git}"
+BRANCH="${ACESTEP_CPP_BRANCH:-}"
 FORCE_FLAGS=""
 CPU_ONLY=0
 
@@ -28,6 +30,7 @@ while [ $# -gt 0 ]; do
         --src)    SRC_DIR="$2"; BUILD_DIR="$SRC_DIR/build"; shift ;;
         --bin)    BIN_DIR="$2"; shift ;;
         --repo)   REPO="$2"; shift ;;
+        --branch) BRANCH="$2"; shift ;;
         --cuda)   FORCE_FLAGS="-DGGML_CUDA=ON" ;;
         --rocm)   FORCE_FLAGS="-DGGML_HIP=ON" ;;
         --vulkan) FORCE_FLAGS="-DGGML_VULKAN=ON" ;;
@@ -60,8 +63,13 @@ fi
 
 # ── Clone or update acestep.cpp ───────────────────────────────────────────────
 if [ ! -d "$SRC_DIR/.git" ]; then
-    echo "Cloning acestep.cpp from $REPO ..."
-    git clone --depth 1 "$REPO" "$SRC_DIR"
+    if [ -n "$BRANCH" ]; then
+        echo "Cloning acestep.cpp from $REPO (branch: $BRANCH) ..."
+        git clone --depth 1 --branch "$BRANCH" "$REPO" "$SRC_DIR"
+    else
+        echo "Cloning acestep.cpp from $REPO ..."
+        git clone --depth 1 "$REPO" "$SRC_DIR"
+    fi
     echo ""
 else
     echo "acestep.cpp source found at $SRC_DIR"
diff --git a/setup.sh b/setup.sh
index 6f3f10a..7ee1af5 100755
--- a/setup.sh
+++ b/setup.sh
@@ -37,6 +37,8 @@ elif [ -n "${ACESTEP_BIN:-}" ] && [ -x "$ACESTEP_BIN" ]; then
 else
   echo ""
   echo "Building acestep.cpp for your hardware (detects GPU automatically)..."
+  echo "  Repo:   ${ACESTEP_CPP_REPO:-https://github.com/audiohacking/acestep.cpp.git}"
+  [ -n "${ACESTEP_CPP_BRANCH:-}" ] && echo "  Branch: $ACESTEP_CPP_BRANCH"
   echo ""
   bash build.sh || {
     echo ""
@@ -46,6 +48,10 @@ else
     echo "    cmake --build acestep.cpp/build --parallel"
     echo "  Then set ACESTEP_BIN_DIR=$(pwd)/bin in .env"
     echo ""
+    echo "  To use a custom fork or branch, set before running setup.sh:"
+    echo "    ACESTEP_CPP_REPO=https://github.com/your-fork/acestep.cpp.git ./setup.sh"
+    echo "    ACESTEP_CPP_BRANCH=my-branch ./setup.sh"
+    echo ""
   }
 fi