diff --git a/iso/builder/build.sh b/iso/builder/build.sh
index 5a2276d..3ff3688 100755
--- a/iso/builder/build.sh
+++ b/iso/builder/build.sh
@@ -69,12 +69,27 @@ mkdir -p "${CACHE_ROOT}"
 : "${GOMODCACHE:=${CACHE_ROOT}/go-mod}"
 export GOCACHE GOMODCACHE
 
-resolve_audit_version() {
+resolve_project_version() {
+    if [ -n "${BEE_VERSION:-}" ]; then
+        echo "${BEE_VERSION}"
+        return 0
+    fi
+
+    if [ -n "${BEE_AUDIT_VERSION:-}" ] && [ -n "${BEE_ISO_VERSION:-}" ] && [ "${BEE_AUDIT_VERSION}" != "${BEE_ISO_VERSION}" ]; then
+        echo "ERROR: BEE_AUDIT_VERSION (${BEE_AUDIT_VERSION}) and BEE_ISO_VERSION (${BEE_ISO_VERSION}) differ; versioning must stay synchronized" >&2
+        exit 1
+    fi
+
     if [ -n "${BEE_AUDIT_VERSION:-}" ]; then
         echo "${BEE_AUDIT_VERSION}"
         return 0
     fi
 
+    if [ -n "${BEE_ISO_VERSION:-}" ]; then
+        echo "${BEE_ISO_VERSION}"
+        return 0
+    fi
+
     tag="$(git -C "${REPO_ROOT}" describe --tags --match 'v[0-9]*' --abbrev=7 --dirty 2>/dev/null || true)"
     case "${tag}" in
         v*)
@@ -97,35 +112,6 @@ resolve_audit_version() {
     date +%Y%m%d
 }
 
-# ISO image versioned separately from the audit binary (iso/v* tags).
-resolve_iso_version() {
-    if [ -n "${BEE_ISO_VERSION:-}" ]; then
-        echo "${BEE_ISO_VERSION}"
-        return 0
-    fi
-
-    # Plain v* tags (e.g. v2.7) take priority — this is the current tagging scheme
-    tag="$(git -C "${REPO_ROOT}" describe --tags --match 'v[0-9]*' --abbrev=7 --dirty 2>/dev/null || true)"
-    case "${tag}" in
-        v*)
-            echo "${tag#v}"
-            return 0
-            ;;
-    esac
-
-    # Legacy iso/v* tags fallback
-    tag="$(git -C "${REPO_ROOT}" describe --tags --match 'iso/v*' --abbrev=7 --dirty 2>/dev/null || true)"
-    case "${tag}" in
-        iso/v*)
-            echo "${tag#iso/v}"
-            return 0
-            ;;
-    esac
-
-    # Fall back to audit version so the name is still meaningful
-    resolve_audit_version
-}
-
 sync_builder_workdir() {
     src_dir="$1"
     dst_dir="$2"
@@ -1018,11 +1004,10 @@ recover_iso_memtest() {
     fi
 }
 
-AUDIT_VERSION_EFFECTIVE="$(resolve_audit_version)"
-ISO_VERSION_EFFECTIVE="$(resolve_iso_version)"
-ISO_BASENAME="easy-bee-${BUILD_VARIANT}-v${ISO_VERSION_EFFECTIVE}-amd64"
+PROJECT_VERSION_EFFECTIVE="$(resolve_project_version)"
+ISO_BASENAME="easy-bee-${BUILD_VARIANT}-v${PROJECT_VERSION_EFFECTIVE}-amd64"
 # Versioned output directory: dist/easy-bee-v4.1/ — all final artefacts live here.
-OUT_DIR="${DIST_DIR}/easy-bee-v${ISO_VERSION_EFFECTIVE}"
+OUT_DIR="${DIST_DIR}/easy-bee-v${PROJECT_VERSION_EFFECTIVE}"
 mkdir -p "${OUT_DIR}"
 LOG_DIR="${OUT_DIR}/${ISO_BASENAME}.logs"
 LOG_ARCHIVE="${OUT_DIR}/${ISO_BASENAME}.logs.tar.gz"
@@ -1198,7 +1183,7 @@ fi
 
 echo "=== bee ISO build (variant: ${BUILD_VARIANT}) ==="
 echo "Debian: ${DEBIAN_VERSION}, Kernel ABI: ${DEBIAN_KERNEL_ABI}, Go: ${GO_VERSION}"
-echo "Audit version: ${AUDIT_VERSION_EFFECTIVE}, ISO version: ${ISO_VERSION_EFFECTIVE}"
+echo "Project version: ${PROJECT_VERSION_EFFECTIVE}"
 echo ""
 
 run_step "sync git submodules" "05-git-submodules" \
@@ -1218,7 +1203,7 @@ if [ "$NEED_BUILD" = "1" ]; then
         "cd '${REPO_ROOT}/audit' && \
         env GOOS=linux GOARCH=amd64 CGO_ENABLED=0 \
             go build \
-            -ldflags '-s -w -X main.Version=${AUDIT_VERSION_EFFECTIVE}' \
+            -ldflags '-s -w -X main.Version=${PROJECT_VERSION_EFFECTIVE}' \
             -o '${BEE_BIN}' \
             ./cmd/bee"
     echo "binary: $BEE_BIN"
@@ -1493,8 +1478,10 @@ else
 fi
 
 cat > "${OVERLAY_STAGE_DIR}/etc/bee-release" <<EOF
-BEE_ISO_VERSION=${ISO_VERSION_EFFECTIVE}
-BEE_AUDIT_VERSION=${AUDIT_VERSION_EFFECTIVE}
+BEE_VERSION=${PROJECT_VERSION_EFFECTIVE}
+export BEE_VERSION
+BEE_ISO_VERSION=${PROJECT_VERSION_EFFECTIVE}
+BEE_AUDIT_VERSION=${PROJECT_VERSION_EFFECTIVE}
 BEE_BUILD_VARIANT=${BUILD_VARIANT}
 BEE_GPU_VENDOR=${BEE_GPU_VENDOR}
 BUILD_DATE=${BUILD_DATE}