diff --git a/rustbpe/Cargo.lock b/rustbpe/Cargo.lock
index 69f8754..80dbd7f 100644
--- a/rustbpe/Cargo.lock
+++ b/rustbpe/Cargo.lock
@@ -230,11 +230,10 @@ dependencies = [
 
 [[package]]
 name = "pyo3"
-version = "0.23.5"
+version = "0.26.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7778bffd85cf38175ac1f545509665d0b9b92a198ca7941f131f85f7a4f9a872"
+checksum = "7ba0117f4212101ee6544044dae45abe1083d30ce7b29c4b5cbdfa2354e07383"
 dependencies = [
- "cfg-if",
  "indoc",
  "libc",
  "memoffset",
@@ -248,19 +247,18 @@ dependencies = [
 
 [[package]]
 name = "pyo3-build-config"
-version = "0.23.5"
+version = "0.26.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "94f6cbe86ef3bf18998d9df6e0f3fc1050a8c5efa409bf712e661a4366e010fb"
+checksum = "4fc6ddaf24947d12a9aa31ac65431fb1b851b8f4365426e182901eabfb87df5f"
 dependencies = [
- "once_cell",
  "target-lexicon",
 ]
 
 [[package]]
 name = "pyo3-ffi"
-version = "0.23.5"
+version = "0.26.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e9f1b4c431c0bb1c8fb0a338709859eed0d030ff6daa34368d3b152a63dfdd8d"
+checksum = "025474d3928738efb38ac36d4744a74a400c901c7596199e20e45d98eb194105"
 dependencies = [
  "libc",
  "pyo3-build-config",
@@ -268,9 +266,9 @@ dependencies = [
 
 [[package]]
 name = "pyo3-log"
-version = "0.12.4"
+version = "0.13.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "45192e5e4a4d2505587e27806c7b710c231c40c56f3bfc19535d0bb25df52264"
+checksum = "d359e20231345f21a3b5b6aea7e73f4dc97e1712ef3bfe2d88997ac6a308d784"
 dependencies = [
  "arc-swap",
  "log",
@@ -279,9 +277,9 @@ dependencies = [
 
 [[package]]
 name = "pyo3-macros"
-version = "0.23.5"
+version = "0.26.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fbc2201328f63c4710f68abdf653c89d8dbc2858b88c5d88b0ff38a75288a9da"
+checksum = "2e64eb489f22fe1c95911b77c44cc41e7c19f3082fc81cce90f657cdc42ffded"
 dependencies = [
  "proc-macro2",
  "pyo3-macros-backend",
@@ -291,9 +289,9 @@ dependencies = [
 
 [[package]]
 name = "pyo3-macros-backend"
-version = "0.23.5"
+version = "0.26.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fca6726ad0f3da9c9de093d6f116a93c1a38e417ed73bf138472cf4064f72028"
+checksum = "100246c0ecf400b475341b8455a9213344569af29a3c841d29270e53102e0fcf"
 dependencies = [
  "heck",
  "proc-macro2",
@@ -400,9 +398,9 @@ dependencies = [
 
 [[package]]
 name = "target-lexicon"
-version = "0.12.16"
+version = "0.13.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "61c41af27dd6d1e27b1b16b489db798443478cef1f06a660c96db617ba5de3b1"
+checksum = "df7f62577c25e07834649fc3b39fafdc597c0a3527dc1c60129201ccfcbaa50c"
 
 [[package]]
 name = "unicode-ident"
diff --git a/rustbpe/Cargo.toml b/rustbpe/Cargo.toml
index 392a828..3e8efd3 100644
--- a/rustbpe/Cargo.toml
+++ b/rustbpe/Cargo.toml
@@ -8,8 +8,8 @@ dary_heap = "0.3"
 indexmap = "2.2"
 fancy-regex = "0.16.1"
 log = "0.4.28"
-pyo3 = { version = "0.23.3", features = ["extension-module"] }
-pyo3-log = "0.12.4"
+pyo3 = { version = "0.26", features = ["extension-module"] }
+pyo3-log = "0.13"
 ahash = "0.8.12"
 rayon = "1.11.0"
 compact_str = "0.9.0"
diff --git a/rustbpe/src/lib.rs b/rustbpe/src/lib.rs
index 273d7f2..81d6670 100644
--- a/rustbpe/src/lib.rs
+++ b/rustbpe/src/lib.rs
@@ -277,7 +277,7 @@ impl Tokenizer {
     pub fn train_from_iterator(
         &mut self,
         py: pyo3::Python<'_>,
-        iterator: &pyo3::Bound<'_, pyo3::PyAny>,
+        iterator: pyo3::Py<pyo3::types::PyIterator>,
         vocab_size: u32,
         buffer_size: usize,
         pattern: Option<String>,
@@ -290,11 +290,6 @@ impl Tokenizer {
         self.compiled_pattern = Regex::new(&pattern_str)
             .map_err(|e| pyo3::exceptions::PyValueError::new_err(format!("Invalid regex pattern: {}", e)))?;
 
-        // Prepare a true Python iterator object
-        let py_iter: pyo3::Py<pyo3::PyAny> = unsafe {
-            pyo3::Py::from_owned_ptr_or_err(py, pyo3::ffi::PyObject_GetIter(iterator.as_ptr()))?
-        };
-
         // Global chunk counts
         let mut counts: AHashMap<CompactString, i32> = AHashMap::new();
 
@@ -307,28 +302,21 @@ impl Tokenizer {
         // Helper: refill `buf` with up to `buffer_size` strings from the Python iterator.
         // Returns Ok(true) if the iterator is exhausted, Ok(false) otherwise.
         let refill = |buf: &mut Vec<String>| -> PyResult<bool> {
-            pyo3::Python::with_gil(|py| {
+            pyo3::Python::attach(|py| {
                 buf.clear();
-                let it = py_iter.bind(py);
+                let mut it = iterator.bind(py).clone();
                 loop {
                     if buf.len() >= buffer_size {
                         return Ok(false);
                     }
-                    // next(it)
-                    let next_obj = unsafe {
-                        pyo3::Bound::from_owned_ptr_or_opt(py, pyo3::ffi::PyIter_Next(it.as_ptr()))
-                    };
-                    match next_obj {
-                        Some(obj) => {
+                    match it.next() {
+                        Some(Ok(obj)) => {
                             let s: String = obj.extract()?;
                             buf.push(s);
-                        }
+                        },
+                        Some(Err(e)) => return Err(e),
                         None => {
-                            if pyo3::PyErr::occurred(py) {
-                                return Err(pyo3::PyErr::fetch(py));
-                            } else {
-                                return Ok(true); // exhausted
-                            }
+                            return Ok(true); // exhausted
                         }
                     }
                 }
@@ -345,7 +333,7 @@ impl Tokenizer {
             total_sequences += buf.len() as u64;
 
             let pattern = self.compiled_pattern.clone();
-            let local: AHashMap<CompactString, i32> = py.allow_threads(|| {
+            let local: AHashMap<CompactString, i32> = py.detach(|| {
                 buf.par_iter()
                     .map(|s| {
                         let mut m: AHashMap<CompactString, i32> = AHashMap::new();