diff --git a/scripts/all.sh b/scripts/all.sh
index 99558e5..6ed6253 100755
--- a/scripts/all.sh
+++ b/scripts/all.sh
@@ -7,6 +7,10 @@ cd "$ROOT"
 # Defaults suitable for automation
 : "${CLEAN:=1}"
 : "${PREFIX:=/usr/local/imap}"
+: "${DEPS_AUTO:=1}"
+
+# Install deps first (Debian/Ubuntu)
+./scripts/deps-debian.sh
 
 ./scripts/apply-patches.sh
 CLEAN="$CLEAN" ./scripts/build.sh
diff --git a/scripts/deps-debian.sh b/scripts/deps-debian.sh
new file mode 100755
index 0000000..2769673
--- /dev/null
+++ b/scripts/deps-debian.sh
@@ -0,0 +1,101 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+usage() {
+  cat <<USAGE
+Usage: $0
+
+Installs required build dependencies on Debian/Ubuntu using apt.
+
+Environment:
+  DEPS_AUTO   (default: 1)  set to 0 to only print missing packages and exit non-zero
+  APT_YES     (default: 1)  set to 0 to run apt without -y
+USAGE
+}
+
+if [[ "${1:-}" == "-h" || "${1:-}" == "--help" ]]; then
+  usage
+  exit 0
+fi
+
+DEPS_AUTO="${DEPS_AUTO:-1}"
+APT_YES="${APT_YES:-1}"
+
+# Must have apt
+if ! command -v apt-get >/dev/null 2>&1; then
+  echo "ERROR: apt-get not found. This script supports Debian/Ubuntu only." >&2
+  exit 1
+fi
+
+# Basic distro check (soft)
+if [[ -r /etc/os-release ]]; then
+  . /etc/os-release
+  case "${ID:-}" in
+    debian|ubuntu|linuxmint|pop) : ;;
+    *)
+      echo "WARN: Detected ID=${ID:-unknown}. Proceeding anyway (apt-based system assumed)." >&2
+      ;;
+  esac
+fi
+
+# Packages needed to build UW-IMAP 2007f with modern toolchains
+PKGS=(
+  build-essential
+  autoconf
+  automake
+  libtool
+  pkg-config
+  libssl-dev
+  libpam0g-dev
+  libc6-dev
+  libcrypt-dev
+  bison
+  flex
+  patch
+  ca-certificates
+)
+
+missing=()
+for p in "${PKGS[@]}"; do
+  if dpkg -s "$p" >/dev/null 2>&1; then
+    continue
+  fi
+  missing+=( "$p" )
+done
+
+if (( ${#missing[@]} == 0 )); then
+  echo "==> Dependencies already satisfied."
+  exit 0
+fi
+
+echo "==> Missing packages:"
+printf '  - %s\n' "${missing[@]}"
+
+if [[ "$DEPS_AUTO" != "1" ]]; then
+  echo "DEPS_AUTO=0 -> not installing automatically." >&2
+  exit 2
+fi
+
+# Choose privilege escalation
+SUDO=""
+if [[ "$(id -u)" -ne 0 ]]; then
+  if command -v sudo >/dev/null 2>&1; then
+    SUDO="sudo"
+  else
+    echo "ERROR: Not running as root and sudo not found." >&2
+    exit 1
+  fi
+fi
+
+yesflag=()
+if [[ "$APT_YES" == "1" ]]; then
+  yesflag=( -y )
+fi
+
+echo "==> Updating apt index"
+$SUDO apt-get update
+
+echo "==> Installing dependencies"
+$SUDO apt-get install "${yesflag[@]}" "${missing[@]}"
+
+echo "==> Done."