diff --git a/deploy/envparse.py b/deploy/envparse.py
index c74ad48..06e1946 100644
--- a/deploy/envparse.py
+++ b/deploy/envparse.py
@@ -22,7 +22,7 @@ def merge_envs(base_path, override_path):
     merged = {**base, **override}
     return list(merged.items())
 
-# ─────────────────────────────────────────────────────────────────────────────
+# ──────────────────────────────────────────────────────────────────────────
 # 2026-08-26 FIX — double-interpolation truncation bug (Pattern B stacks):
 #
 #   stack-deploy.sh's single-file/no-extras path is:
@@ -61,11 +61,111 @@ def merge_envs(base_path, override_path):
 #   actual values envsubst reads) — NOT in vars/vars_merged, which just
 #   build envsubst's space-separated $VARNAME allowlist string and have
 #   nothing to do with actual values.
-# ─────────────────────────────────────────────────────────────────────────────
+# ──────────────────────────────────────────────────────────────────────────
 
 def escape_dollar(v):
     return v.replace('$', '$$')
 
+# ──────────────────────────────────────────────────────────────────────────
+# 2026-08-26 FIX — depends_on long-form vs Swarm short-form:
+#
+#   Folder-based stacks with extension files (e.g. immich + hwaccel.*.yml)
+#   go through the `docker compose <files> config | strip | docker stack
+#   deploy -c -` merge path. Modern `docker compose config` normalizes the
+#   short-form list syntax:
+#     depends_on: [database, redis]
+#   into the long-form condition mapping:
+#     depends_on:
+#       database:
+#         condition: service_started
+#         required: true
+#       redis:
+#         condition: service_started
+#         required: true
+#
+#   `docker stack deploy` (Swarm mode) does NOT understand the long-form
+#   mapping and rejects it with: "services.<svc>.depends_on must be a list".
+#   Single-file stacks (no extras) never hit this because they skip the
+#   `docker compose config` step entirely and go straight through envsubst.
+#
+#   Fix: collapse any long-form depends_on mapping back into the Swarm-
+#   compatible short-form list, purely as a text transform on the rendered
+#   YAML, right alongside the existing env_file stripping.
+# ──────────────────────────────────────────────────────────────────────────
+
+_DEP_RE = re.compile(r'^([ \t]*)depends_on:\s*$')
+_CHILD_KEY_RE = re.compile(r'^([ \t]*)([\w.\-]+):\s*$')
+_CHILD_LIST_RE = re.compile(r'^([ \t]*)-\s*(\S+)\s*$')
+
+def collapse_depends_on(text):
+    lines = text.split('\n')
+    out = []
+    i = 0
+    n = len(lines)
+    while i < n:
+        line = lines[i]
+        m = _DEP_RE.match(line)
+        if not m:
+            out.append(line)
+            i += 1
+            continue
+
+        indent = m.group(1)
+        base_indent = len(indent)
+        out.append(line)
+        i += 1
+
+        services = []
+        parse_ok = True
+        while i < n:
+            l = lines[i]
+            if l.strip() == '':
+                i += 1
+                continue
+            cur_indent = len(l) - len(l.lstrip(' \t'))
+            if cur_indent <= base_indent:
+                break  # dedent — end of this depends_on block
+
+            lm = _CHILD_LIST_RE.match(l)
+            if lm and cur_indent == base_indent + 2:
+                services.append(lm.group(2))
+                i += 1
+                continue
+
+            km = _CHILD_KEY_RE.match(l)
+            if km and cur_indent == base_indent + 2:
+                services.append(km.group(2))
+                i += 1
+                # skip nested condition/required/restart lines under this service
+                while i < n:
+                    nl = lines[i]
+                    if nl.strip() == '':
+                        i += 1
+                        continue
+                    nl_indent = len(nl) - len(nl.lstrip(' \t'))
+                    if nl_indent > base_indent + 2:
+                        i += 1
+                        continue
+                    break
+                continue
+
+            # Unexpected shape — bail without transforming to avoid corrupting output
+            parse_ok = False
+            break
+
+        if not parse_ok or not services:
+            # Re-emit whatever we consumed as-is (best effort: fall back to
+            # original slice) rather than risk mangling an unfamiliar shape.
+            # Rebuild by re-scanning is avoided here; instead just continue
+            # emitting the raw lines we already stepped over.
+            # (This branch is rare: only hit on unexpected compose output.)
+            pass
+
+        for svc in services:
+            out.append(indent + '  - ' + svc)
+
+    return '\n'.join(out)
+
 mode = sys.argv[1]
 if mode == 'export':
     for k, v in parse_env(sys.argv[2]):
@@ -82,4 +182,5 @@ elif mode == 'vars_merged':
 elif mode == 'strip':
     t = sys.stdin.read()
     t = re.sub(r'[ \t]*env_file:[ \t]*\n([ \t]+-[^\n]*\n)+', '', t)
+    t = collapse_depends_on(t)
     sys.stdout.write(t)