diff --git a/liboptv/include/calibration.h b/liboptv/include/calibration.h
index f4d0c07f..7902c7fe 100644
--- a/liboptv/include/calibration.h
+++ b/liboptv/include/calibration.h
@@ -58,10 +58,8 @@ typedef struct {
 
 
 
-int write_ori(Exterior Ex, Interior I, Glass G, ap_52 ap, char *filename, 
-    char *add_file);
-int read_ori (Exterior Ex[], Interior I[], Glass G[], char *ori_file, 
-    ap_52 addp[], char *add_file, char *add_fallback);
+int write_ori(Exterior ext_par, Interior int_par, Glass glass_par, ap_52 added_par, char *filename, char *add_file);
+int read_ori (Exterior ext_par[], Interior int_par[], Glass glass_par[], char *ori_file, ap_52 added_par[], char *add_file, char *add_fallback);
 int compare_exterior(Exterior *e1, Exterior *e2);
 int compare_interior(Interior *i1, Interior *i2);
 int compare_glass(Glass *g1, Glass *g2);
diff --git a/liboptv/include/ray_tracing.h b/liboptv/include/ray_tracing.h
index 7305d4d2..f23c2ec6 100644
--- a/liboptv/include/ray_tracing.h
+++ b/liboptv/include/ray_tracing.h
@@ -23,7 +23,7 @@ void ray_tracing (double x
 				, double X[3]
 				, double a[3]);
 				
-void old_ray_tracing (double x, double y, Exterior Ex, Interior I, Glass G,\
+void old_ray_tracing (double x, double y, Exterior ext_par, Interior int_par, Glass glass_par,\
                   mm_np mm, double *Xb2, double *Yb2, double *Zb2, \
                   double *a3, double *b3,double *c3);
 
diff --git a/liboptv/src/orientation.c b/liboptv/src/orientation.c
index 21f23c22..20387627 100644
--- a/liboptv/src/orientation.c
+++ b/liboptv/src/orientation.c
@@ -723,10 +723,19 @@ int read_man_ori_fix(vec3d fix4[4], char* calblock_filename,
         goto handle_error;
     }
 
-    for (i=0; i<cam; i++)
-        fscanf (fpp, "%d %d %d %d \n", &dummy, &dummy, &dummy, &dummy);
-    fscanf (fpp, "%d %d %d %d \n", &nr[0], &nr[1], &nr[2], &nr[3]);
-    fclose (fpp);
+    for (i=0; i<cam; i++) {
+        if (fscanf(fpp, "%d %d %d %d \n", &dummy, &dummy, &dummy, &dummy) != 4) {
+            printf("Error reading manual orientation file %s\n", man_ori_filename);
+            fclose(fpp);
+            return 0;
+        }
+    }
+    if (fscanf(fpp, "%d %d %d %d \n", &nr[0], &nr[1], &nr[2], &nr[3]) != 4) {
+        printf("Error reading manual orientation file %s\n", man_ori_filename);
+        fclose(fpp);
+        return 0;
+    }
+    fclose(fpp);
 
     /* read the id and positions of the fixed points, assign the pre-defined to fix4 */
     fix = read_calblock(&num_fix, calblock_filename);
diff --git a/liboptv/src/tracking_frame_buf.c b/liboptv/src/tracking_frame_buf.c
index a75b4c6e..9e53d90e 100644
--- a/liboptv/src/tracking_frame_buf.c
+++ b/liboptv/src/tracking_frame_buf.c
@@ -10,6 +10,7 @@ reading targets, correspondences, etc.
 #include <stdio.h>
 #include <stdlib.h>
 #include "tracking_frame_buf.h"
+#include "calibration.h"
 
 /* Check that target t1 is equal to target t2, i.e. all their fields are equal.
  * 
diff --git a/py_bind/optv/correspondences.pyx b/py_bind/optv/correspondences.pyx
index 1b14fc3b..3e21ff67 100644
--- a/py_bind/optv/correspondences.pyx
+++ b/py_bind/optv/correspondences.pyx
@@ -84,11 +84,11 @@ cdef class MatchedCoords:
         """
         cdef:
             np.ndarray[ndim=2, dtype=np.float64_t] pos
-            np.ndarray[ndim=1, dtype=np.int_t] pnr
+            np.ndarray[ndim=1, dtype=np.int32_t] pnr
             int pt
         
         pos = np.empty((self._num_pts, 2))
-        pnr = np.empty(self._num_pts, dtype=np.int_)
+        pnr = np.empty(self._num_pts, dtype=np.int32)
         
         for pt in range(self._num_pts):
             pos[pt,0] = self.buf[pt].x
@@ -97,7 +97,7 @@ cdef class MatchedCoords:
         
         return pos, pnr
     
-    def get_by_pnrs(self, np.ndarray[ndim=1, dtype=np.int_t] pnrs):
+    def get_by_pnrs(self, np.ndarray[ndim=1, dtype=np.int32_t] pnrs):
         """
         Return the flat positions of points whose pnr property is given, as an
         (n,2) flat position array. Assumes all pnrs are to be found, otherwise
@@ -160,7 +160,7 @@ def correspondences(list img_pts, list flat_coords, list cals,
             num_cams * sizeof(coord_2d *))
         frame frm
         
-        np.ndarray[ndim=2, dtype=np.int_t] clique_ids
+        np.ndarray[ndim=2, dtype=np.int32_t] clique_ids
         np.ndarray[ndim=3, dtype=np.float64_t] clique_targs
         
         # Return buffers:
diff --git a/py_bind/optv/orientation.pyx b/py_bind/optv/orientation.pyx
index b3ef927e..473689ba 100644
--- a/py_bind/optv/orientation.pyx
+++ b/py_bind/optv/orientation.pyx
@@ -263,7 +263,7 @@ def full_calibration(Calibration cal,
     cdef:
         vec3d *ref_coord
         np.ndarray[ndim=2, dtype=pos_t] ret
-        np.ndarray[ndim=1, dtype=np.int_t] used
+        np.ndarray[ndim=1, dtype=np.int32_t] used
         np.ndarray[ndim=1, dtype=pos_t] err_est
         orient_par *orip
         double *residuals
diff --git a/py_bind/optv/parameters.pyx b/py_bind/optv/parameters.pyx
index a294d224..0f83ee8e 100644
--- a/py_bind/optv/parameters.pyx
+++ b/py_bind/optv/parameters.pyx
@@ -402,7 +402,7 @@ cdef class SequenceParams:
         cdef char * c_str = self._sequence_par[0].img_base_name[cam]
         # FILEPATH: /home/user/Documents/repos/openptv/py_bind/optv/parameters.pyx
         # BEGIN: ed8c6549bwf9
-        cdef char* c_str = ...
+        # cdef char* c_str = ...
         py_str = c_str
         return py_str
         # END: ed8c6549bwf9
diff --git a/py_bind/optv/segmentation.pyx b/py_bind/optv/segmentation.pyx
index d40dff9e..d04f0a99 100644
--- a/py_bind/optv/segmentation.pyx
+++ b/py_bind/optv/segmentation.pyx
@@ -21,7 +21,7 @@ DTYPE = np.uint8
 # "ctypedef" assigns a corresponding compile-time type to DTYPE_t. For
 # every type in the numpy module there's a corresponding compile-time
 # type with a _t-suffix.
-ctypedef np.int_t DTYPE_t
+ctypedef np.uint8_t DTYPE_t
 
 from optv.parameters cimport TargetParams, ControlParams
 from optv.tracking_framebuf cimport TargetArray
diff --git a/py_bind/optv/transforms.pxd b/py_bind/optv/transforms.pxd
index bc573b40..7765a23b 100644
--- a/py_bind/optv/transforms.pxd
+++ b/py_bind/optv/transforms.pxd
@@ -7,22 +7,22 @@ cdef extern from "optv/trafo.h":
                          , double * y_metric
                          , double x_pixel
                          , double y_pixel
-                         , control_par * parameters)
+                         , control_par * parameters) noexcept
     void metric_to_pixel(double * x_pixel
                          , double * y_pixel
                          , double x_metric
                          , double y_metric
-                         , control_par * parameters)
+                         , control_par * parameters) noexcept
     void correct_brown_affin (double x
                          , double y
                          , ap_52 ap
                          , double * x1
-                         , double * y1)                    
+                         , double * y1) noexcept                    
     void distort_brown_affin (double x
                          , double y
                          , ap_52 ap
                          , double * x1
-                         , double * y1)
+                         , double * y1) noexcept
     
     void correct_brown_affine_exact(double x, double y, ap_52 ap, 
     double *x1, double *y1, double tol)
diff --git a/py_bind/optv/transforms.pyx b/py_bind/optv/transforms.pyx
index 2bcd7acb..b9f9afbe 100644
--- a/py_bind/optv/transforms.pyx
+++ b/py_bind/optv/transforms.pyx
@@ -53,18 +53,24 @@ def convert_arr_metric_to_pixel(np.ndarray[np.float_t, ndim=2] input,
     '''
     return convert_generic(input, control._control_par, out, metric_to_pixel)
 
-cdef convert_generic(np.ndarray[np.float_t, ndim=2] input,
-                        control_par * c_control,
-                        np.ndarray[np.float_t, ndim=2] out,
-                        void convert_function(double * , double * , double, double , control_par *)) noexcept nogil:
+cdef convert_generic(
+                     np.ndarray[np.float_t, ndim=2] input,
+                     control_par * c_control,
+                     np.ndarray[np.float_t, ndim=2] out,
+                     void (*convert_function)(double *, double *, double, double, control_par *)
+                    noexcept ):
+    # Acquire GIL before calling any GIL-requiring functions
     out = check_inputs(input, out)
 
     for i in range(input.shape[0]):
-        convert_function(< double *> np.PyArray_GETPTR2(out, i, 0)
-                        , < double *> np.PyArray_GETPTR2(out, i, 1)
-                        , (< double *> np.PyArray_GETPTR2(input, i, 0))[0]
-                        , (< double *> np.PyArray_GETPTR2(input, i, 1))[0]
-                        , c_control)
+        convert_function(<double *> np.PyArray_GETPTR2(out, i, 0),
+                        <double *> np.PyArray_GETPTR2(out, i, 1),
+                        (<double *> np.PyArray_GETPTR2(input, i, 0))[0],
+                        (<double *> np.PyArray_GETPTR2(input, i, 1))[0],
+                        c_control)
+
+    # Acquire GIL before returning the Python object
+
     return out
 
 # Affine #
@@ -103,7 +109,7 @@ def distort_arr_brown_affine(np.ndarray[np.float_t, ndim=2] input,
 cdef brown_affine_generic(np.ndarray[np.float_t, ndim=2] input,
                         ap_52 c_ap_52,
                         np.ndarray[np.float_t, ndim=2] out,
-                        void affine_function(double, double, ap_52 , double * , double *)):
+                        void (*affine_function)(double, double, ap_52, double *, double *) noexcept):
     out = check_inputs(input, out)
     
     for i in range(input.shape[0]):
diff --git a/py_bind/pyproject.toml b/py_bind/pyproject.toml
index 4f45da8c..068bf258 100644
--- a/py_bind/pyproject.toml
+++ b/py_bind/pyproject.toml
@@ -4,8 +4,8 @@ requires = [
     "packaging==20.5; platform_machine=='arm64'",  # macos M1
     "setuptools==59.2.0",
     "wheel==0.37.0",
-    "Cython>=0.29.28,<3.0",  # Note: keep in sync with tools/cythonize.py
-    "numpy>=1.17.3, <1.24",
+    "Cython",  # Note: keep in sync with tools/cythonize.py
+    "numpy",
 ]
 
 [tool.cibuildwheel]
diff --git a/py_bind/setup.py b/py_bind/setup.py
index d13b621c..834847c1 100644
--- a/py_bind/setup.py
+++ b/py_bind/setup.py
@@ -82,7 +82,7 @@ def get_numpy_include_dir():
                 del builtins.__NUMPY_SETUP__
             import importlib
             import numpy
-            importlib.reload(numpy)
+            # importlib.reload(numpy)
         else:
             import builtins
             if hasattr(__builtin__, '__NUMPY_SETUP__'):
@@ -122,7 +122,7 @@ def get_liboptv_sources():
 
 def mk_ext(name, files):
     # Do not specify include dirs, as they require numpy to be installed. Add them in BuildExt
-    return Extension(name, files + get_liboptv_sources())
+    return Extension(name, files + get_liboptv_sources(), define_macros=[('NPY_NO_DEPRECATED_API', 'NPY_1_7_API_VERSION')])
 
 
 ext_mods = [
@@ -154,9 +154,9 @@ def mk_ext(name, files):
     package_data={
         'optv': ['*.pxd', '*.c', '*.h'],
     },
-    version='0.2.8',
+    version='0.3.0',
     install_requires=[
-        'numpy<1.24',
+        'numpy',
         'pyyaml',
     ],
     setup_requires=['numpy'],