diff --git a/unsloth_zoo/compiler.py b/unsloth_zoo/compiler.py
index ee22f1aea..ba13ceee0 100644
--- a/unsloth_zoo/compiler.py
+++ b/unsloth_zoo/compiler.py
@@ -394,7 +394,14 @@ def higher_precision_softmax(source):
         r"([^,]{1,}), "
         r"(dim[ ]?\=[ ]?[\-0-9]{1,2})"
         r"(\,[ ]?dtype[^\)]{1,})?"
-        r"\)",
+        r"\)"
+        # Idempotency: skip the rewrite when the softmax(...) is already
+        # followed by `.to(<variable>.dtype)`. Without this lookahead,
+        # re-running higher_precision_softmax on already-rewritten source
+        # appends another `.to(<variable>.dtype)` per pass (the existing
+        # cast is outside the matched span and `source.replace(...)`
+        # leaves it in place, producing `softmax(...).to(x.dtype).to(x.dtype)`).
+        r"(?!\s*\.to\(\s*\2\s*\.dtype\s*\))",
         source,
     )
     for item in softmax_objects: