diff --git a/Dockerfile b/Dockerfile
index 380e4dfe..12dd5fed 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -373,6 +373,7 @@ RUN --mount=type=cache,target=/root/.cache/uv,sharing=locked,id=uv-$TARGETARCH$T
 # Initialize an empty image collection without rerunning dependency installs.
 WORKDIR "$DATA_DIR"
 RUN echo "[+] Initializing image collection..." \
+    && find "$DATA_DIR" -mindepth 1 -maxdepth 1 -exec rm -rf {} + \
     && PUID=0 PGID=0 archivebox init \
     && find "$DATA_DIR" -type d -name __pycache__ -prune -exec rm -rf {} + \
     && find "$DATA_DIR" -type f \( -name '*.pyc' -o -name '*.pyo' \) -delete \
diff --git a/Dockerfile.multistage b/Dockerfile.multistage
index 4fe8246f..40ee9b30 100644
--- a/Dockerfile.multistage
+++ b/Dockerfile.multistage
@@ -184,6 +184,7 @@ RUN echo "[*] Setting up $ARCHIVEBOX_USER user uid=${DEFAULT_PUID}..." \
 
 WORKDIR "$DATA_DIR"
 RUN echo "[+] Initializing image collection..." \
+    && find "$DATA_DIR" -mindepth 1 -maxdepth 1 -exec rm -rf {} + \
     && PUID=0 PGID=0 archivebox init \
     && find "$DATA_DIR" -type d -name __pycache__ -prune -exec rm -rf {} + \
     && find "$DATA_DIR" -type f \( -name '*.pyc' -o -name '*.pyo' \) -delete \
diff --git a/archivebox/tests/test_dockerfiles.py b/archivebox/tests/test_dockerfiles.py
index f3ee48f4..299dab83 100644
--- a/archivebox/tests/test_dockerfiles.py
+++ b/archivebox/tests/test_dockerfiles.py
@@ -91,3 +91,9 @@ def test_dockerfile_build_installs_disable_release_age_gate() -> None:
 def test_dockerfiles_do_not_queue_optional_binaries_during_validation() -> None:
     for dockerfile_name in ("Dockerfile", "Dockerfile.multistage"):
         assert _bare_archivebox_install_commands(REPO_ROOT / dockerfile_name) == []
+
+
+def test_dockerfiles_clean_build_data_dir_before_init() -> None:
+    for dockerfile_name in ("Dockerfile", "Dockerfile.multistage"):
+        text = (REPO_ROOT / dockerfile_name).read_text()
+        assert 'find "$DATA_DIR" -mindepth 1 -maxdepth 1 -exec rm -rf {} +' in text