diff --git a/app/calibration.py b/app/calibration.py
index 3a51102..eb95d3d 100644
--- a/app/calibration.py
+++ b/app/calibration.py
@@ -76,8 +76,8 @@ log = logging.getLogger("chat-saiden.calibration")
 # FALLBACK_VOICES: used when no .pcart config is found.
 # These are the known-good piper voice IDs shipped with the TTS host.
 FALLBACK_VOICES: dict[str, str] = {
-    "en": "en_US-lessac-medium",
-    "pl": "pl_PL-gosia-medium",
+    "en": "bt7274-en",
+    "pl": "bt7274-pl",
 }
 
 # Populated at module load from the persona's cart.toml (see _load_persona_voices).