diff --git a/src/baudolo/backup/compose.py b/src/baudolo/backup/compose.py
index 6a2a011..b428206 100644
--- a/src/baudolo/backup/compose.py
+++ b/src/baudolo/backup/compose.py
@@ -4,7 +4,7 @@ import os
 import shutil
 import subprocess
 from pathlib import Path
-from typing import List
+from typing import List, Optional
 
 
 def _build_compose_cmd(project_dir: str, passthrough: List[str]) -> List[str]:
@@ -30,6 +30,37 @@ def _build_compose_cmd(project_dir: str, passthrough: List[str]) -> List[str]:
     raise RuntimeError("Neither 'compose' nor 'docker' found in PATH")
 
 
+def _find_compose_file(project_dir: str) -> Optional[Path]:
+    """
+    Detect a compose file in `project_dir` (case-insensitive).
+
+    Supported names:
+    - compose.yml / compose.yaml
+    - docker-compose.yml / docker-compose.yaml
+    """
+    pdir = Path(project_dir)
+    if not pdir.is_dir():
+        return None
+
+    # Map lowercase filename -> actual Path (preserves original casing)
+    by_lower = {p.name.lower(): p for p in pdir.iterdir() if p.is_file()}
+
+    # Preferred order (policy decision)
+    candidates = [
+        "docker-compose.yml",
+        "docker-compose.yaml",
+        "compose.yml",
+        "compose.yaml",
+    ]
+
+    for name in candidates:
+        found = by_lower.get(name)
+        if found is not None:
+            return found
+
+    return None
+
+
 def hard_restart_docker_services(dir_path: str) -> None:
     print(f"Hard restart compose services in: {dir_path}", flush=True)
 
@@ -44,7 +75,8 @@ def hard_restart_docker_services(dir_path: str) -> None:
 
 
 def handle_docker_compose_services(
-    parent_directory: str, hard_restart_required: list[str]
+    parent_directory: str,
+    hard_restart_required: list[str],
 ) -> None:
     for entry in os.scandir(parent_directory):
         if not entry.is_dir():
@@ -52,11 +84,12 @@ def handle_docker_compose_services(
 
         dir_path = entry.path
         name = os.path.basename(dir_path)
-        compose_file = os.path.join(dir_path, "docker-compose.yml")
 
         print(f"Checking directory: {dir_path}", flush=True)
-        if not os.path.isfile(compose_file):
-            print("No docker-compose.yml found. Skipping.", flush=True)
+
+        compose_file = _find_compose_file(dir_path)
+        if compose_file is None:
+            print("No supported compose file found. Skipping.", flush=True)
             continue
 
         if name in hard_restart_required:
diff --git a/tests/unit/backup/test_compose.py b/tests/unit/backup/test_compose.py
index d240dd1..bf6aa67 100644
--- a/tests/unit/backup/test_compose.py
+++ b/tests/unit/backup/test_compose.py
@@ -23,6 +23,7 @@ def _setup_compose_dir(
     tmp_path: Path,
     name: str = "mailu",
     *,
+    compose_name: str = "docker-compose.yml",
     with_override: bool = False,
     with_ca_override: bool = False,
     env_layout: str | None = None,  # None | ".env" | ".env/env"
@@ -30,7 +31,7 @@ def _setup_compose_dir(
     d = tmp_path / name
     d.mkdir(parents=True, exist_ok=True)
 
-    _touch(d / "docker-compose.yml")
+    _touch(d / compose_name)
 
     if with_override:
         _touch(d / "docker-compose.override.yml")
@@ -53,11 +54,45 @@ class TestCompose(unittest.TestCase):
 
         cls.compose_mod = mod
 
+    def test_find_compose_file_supports_all_valid_names_case_insensitive(self) -> None:
+        with tempfile.TemporaryDirectory() as td:
+            tmp_path = Path(td)
+
+            variants = [
+                "compose.yml",
+                "compose.yaml",
+                "docker-compose.yml",
+                "docker-compose.yaml",
+                "docker-compose.yAml",
+            ]
+
+            for i, name in enumerate(variants):
+                d = _setup_compose_dir(
+                    tmp_path,
+                    name=f"project{i}",
+                    compose_name=name,
+                )
+                found = self.compose_mod._find_compose_file(str(d))
+                self.assertIsNotNone(found)
+                self.assertEqual(found.name, name)
+
+    def test_find_compose_file_returns_none_when_missing(self) -> None:
+        with tempfile.TemporaryDirectory() as td:
+            tmp_path = Path(td)
+            d = tmp_path / "empty"
+            d.mkdir(parents=True, exist_ok=True)
+
+            found = self.compose_mod._find_compose_file(str(d))
+            self.assertIsNone(found)
+
     def test_build_cmd_uses_wrapper_when_present(self) -> None:
         with tempfile.TemporaryDirectory() as td:
             tmp_path = Path(td)
             d = _setup_compose_dir(
-                tmp_path, with_override=True, with_ca_override=True, env_layout=".env"
+                tmp_path,
+                with_override=True,
+                with_ca_override=True,
+                env_layout=".env",
             )
 
             def fake_which(name: str):