diff --git a/bindings/python/src/tokenizer.rs b/bindings/python/src/tokenizer.rs
index d2e61ee1c..da8c74a9c 100644
--- a/bindings/python/src/tokenizer.rs
+++ b/bindings/python/src/tokenizer.rs
@@ -1,11 +1,12 @@
 use std::collections::{hash_map::DefaultHasher, HashMap};
 use std::hash::{Hash, Hasher};
 
-use numpy::PyArray1;
+use numpy::npyffi;
 use pyo3::class::basic::CompareOp;
 use pyo3::exceptions;
 use pyo3::prelude::*;
 use pyo3::types::*;
+use pyo3::AsPyPointer;
 use tk::models::bpe::BPE;
 use tk::tokenizer::{
     Model, PaddingDirection, PaddingParams, PaddingStrategy, PostProcessor, TokenizerImpl,
@@ -258,8 +259,24 @@ impl<'s> From<TextInputSequence<'s>> for tk::InputSequence<'s> {
 struct PyArrayUnicode(Vec<String>);
 impl FromPyObject<'_> for PyArrayUnicode {
     fn extract(ob: &PyAny) -> PyResult<Self> {
-        let array = ob.downcast::<PyArray1<u8>>()?;
-        let arr = array.as_array_ptr();
+        if unsafe { npyffi::PyArray_Check(ob.py(), ob.as_ptr()) } == 0 {
+            return Err(exceptions::PyTypeError::new_err("Expected an np.array"));
+        }
+        let arr = ob.as_ptr() as *mut npyffi::PyArrayObject;
+        if unsafe { (*arr).nd } != 1 {
+            return Err(exceptions::PyTypeError::new_err(
+                "Expected a 1 dimensional np.array",
+            ));
+        }
+        if unsafe { (*arr).flags }
+            & (npyffi::NPY_ARRAY_C_CONTIGUOUS | npyffi::NPY_ARRAY_F_CONTIGUOUS)
+            == 0
+        {
+            return Err(exceptions::PyTypeError::new_err(
+                "Expected a contiguous np.array",
+            ));
+        }
+        let n_elem = unsafe { *(*arr).dimensions } as usize;
         let (type_num, elsize, alignment, data) = unsafe {
             let desc = (*arr).descr;
             (
@@ -269,7 +286,6 @@ impl FromPyObject<'_> for PyArrayUnicode {
                 (*arr).data,
             )
         };
-        let n_elem = array.shape()[0];
 
         // type_num == 19 => Unicode
         if type_num != 19 {
@@ -310,10 +326,27 @@ impl From<PyArrayUnicode> for tk::InputSequence<'_> {
 struct PyArrayStr(Vec<String>);
 impl FromPyObject<'_> for PyArrayStr {
     fn extract(ob: &PyAny) -> PyResult<Self> {
-        let array = ob.downcast::<PyArray1<u8>>()?;
-        let arr = array.as_array_ptr();
+        if unsafe { npyffi::PyArray_Check(ob.py(), ob.as_ptr()) } == 0 {
+            return Err(exceptions::PyTypeError::new_err("Expected an np.array"));
+        }
+        let arr = ob.as_ptr() as *mut npyffi::PyArrayObject;
+
+        if unsafe { (*arr).nd } != 1 {
+            return Err(exceptions::PyTypeError::new_err(
+                "Expected a 1 dimensional np.array",
+            ));
+        }
+        if unsafe { (*arr).flags }
+            & (npyffi::NPY_ARRAY_C_CONTIGUOUS | npyffi::NPY_ARRAY_F_CONTIGUOUS)
+            == 0
+        {
+            return Err(exceptions::PyTypeError::new_err(
+                "Expected a contiguous np.array",
+            ));
+        }
+        let n_elem = unsafe { *(*arr).dimensions } as usize;
+
         let (type_num, data) = unsafe { ((*(*arr).descr).type_num, (*arr).data) };
-        let n_elem = array.shape()[0];
 
         if type_num != 17 {
             return Err(exceptions::PyTypeError::new_err(