diff --git a/dream-server/bin/dream-host-agent.py b/dream-server/bin/dream-host-agent.py
index 21fc7642..b8eb9fe7 100755
--- a/dream-server/bin/dream-host-agent.py
+++ b/dream-server/bin/dream-host-agent.py
@@ -1148,7 +1148,7 @@ def _run_install():
                 _write_progress(service_id, "starting", "Starting container...")
                 _precreate_data_dirs(service_id)
                 start_result = subprocess.run(
-                    ["docker", "compose"] + flags + ["up", "-d", "--no-deps", service_id],
+                    ["docker", "compose"] + flags + ["up", "-d", service_id],
                     cwd=str(INSTALL_DIR), capture_output=True, text=True,
                     timeout=SUBPROCESS_TIMEOUT_START,
                 )
diff --git a/dream-server/extensions/services/dashboard-api/tests/test_host_agent.py b/dream-server/extensions/services/dashboard-api/tests/test_host_agent.py
index fef1430b..b07a581f 100644
--- a/dream-server/extensions/services/dashboard-api/tests/test_host_agent.py
+++ b/dream-server/extensions/services/dashboard-api/tests/test_host_agent.py
@@ -284,6 +284,43 @@ def test_setup_hook_uses_resolve_hook_with_post_install(self):
         )
 
 
+# --- Install "up -d" must not use --no-deps (regression) ---
+#
+# _handle_install previously passed --no-deps to `docker compose up -d`, which
+# prevented an extension's private sidecar services (declared in its own
+# compose fragment) from starting — including cross-extension depends_on
+# relationships like perplexica -> searxng. The fix removes --no-deps from
+# the install path only; docker_compose_recreate (used for core-service
+# force-recreate after a model swap) intentionally keeps --no-deps.
+
+
+class TestInstallStartCommandNoDeps:
+
+    def _install_source(self):
+        import inspect
+        return inspect.getsource(_mod.AgentHandler._handle_install)
+
+    def _recreate_source(self):
+        import inspect
+        return inspect.getsource(_mod.docker_compose_recreate)
+
+    def test_install_up_command_does_not_pass_no_deps(self):
+        src = self._install_source()
+        assert '"--no-deps"' not in src and "'--no-deps'" not in src, (
+            "_handle_install must not pass --no-deps to `docker compose up -d`; "
+            "extensions with private sidecars or cross-extension depends_on "
+            "need compose to bring dependencies up."
+        )
+
+    def test_docker_compose_recreate_still_uses_no_deps(self):
+        src = self._recreate_source()
+        assert '"--no-deps"' in src or "'--no-deps'" in src, (
+            "docker_compose_recreate must keep --no-deps; "
+            "core-service recreation (e.g. after a model swap) is intentionally "
+            "scoped to the named services only."
+        )
+
+
 # --- _handle_env_update ---