diff --git a/xtts/f5tts/bridge.py b/xtts/f5tts/bridge.py
index 15f39d4..0d90273 100644
--- a/xtts/f5tts/bridge.py
+++ b/xtts/f5tts/bridge.py
@@ -268,7 +268,15 @@ def split_sentences(text: str, max_len: int = 350) -> list[str]:
 
 
 def float_to_pcm16(wav: np.ndarray) -> bytes:
-    """Float32 (-1..+1) → int16 little-endian bytes."""
+    """Float32 (-1..+1) → int16 little-endian bytes.
+
+    F5-TTS generiert gelegentlich NaN/Inf bei Instabilitaeten — ohne sanitize
+    waere der Cast zu int16 undefiniert (RuntimeWarning + kaputter Sound).
+    """
+    nan_count = int(np.isnan(wav).sum() + np.isinf(wav).sum())
+    if nan_count > 0:
+        logger.warning("F5-TTS Output enthaelt %d NaN/Inf samples — ersetze mit 0", nan_count)
+        wav = np.nan_to_num(wav, nan=0.0, posinf=1.0, neginf=-1.0)
     wav = np.clip(wav, -1.0, 1.0)
     pcm = (wav * 32767.0).astype(np.int16)
     return pcm.tobytes()