diff --git a/c/_phonopy.c b/c/_phonopy.c
index e5aa7d8f..4fed141c 100644
--- a/c/_phonopy.c
+++ b/c/_phonopy.c
@@ -444,7 +444,6 @@ static PyObject * py_gsv_set_smallest_vectors(PyObject *self, PyObject *args)
   reduced_basis = (double(*)[3])PyArray_DATA(py_reduced_basis);
   trans_mat = (int(*)[3])PyArray_DATA(py_trans_mat);
 
-
   gsv_set_smallest_vectors(smallest_vectors,
                            multiplicity,
                            pos_to,
@@ -1295,16 +1294,14 @@ static PyObject * py_get_tetrahedra_frequenies(PyObject *self, PyObject *args)
 
   double* freq_tetras;
   size_t* grid_points;
-  int num_gp_in;
   int* mesh;
   int (*grid_address)[3];
   size_t* gp_ir_index;
   int (*relative_grid_address)[3];
   double* frequencies;
-  int num_band;
 
   int is_shift[3] = {0, 0, 0};
-  size_t i, j, k, gp;
+  size_t i, j, k, gp, num_gp_in, num_band;
   int g_addr[3];
   int address_double[3];
 
@@ -1321,13 +1318,13 @@ static PyObject * py_get_tetrahedra_frequenies(PyObject *self, PyObject *args)
 
   freq_tetras = (double*)PyArray_DATA(py_freq_tetras);
   grid_points = (size_t*)PyArray_DATA(py_grid_points);
-  num_gp_in = (int)PyArray_DIMS(py_grid_points)[0];
+  num_gp_in = PyArray_DIMS(py_grid_points)[0];
   mesh = (int*)PyArray_DATA(py_mesh);
   grid_address = (int(*)[3])PyArray_DATA(py_grid_address);
   gp_ir_index = (size_t*)PyArray_DATA(py_gp_ir_index);
   relative_grid_address = (int(*)[3])PyArray_DATA(py_relative_grid_address);
   frequencies = (double*)PyArray_DATA(py_frequencies);
-  num_band = (int)PyArray_DIMS(py_frequencies)[1];
+  num_band = PyArray_DIMS(py_frequencies)[1];
 
   for (i = 0; i < num_gp_in;  i++) {
 #pragma omp parallel for private(k, g_addr, gp, address_double)
@@ -1363,13 +1360,10 @@ static PyObject * py_tetrahedron_method_dos(PyObject *self, PyObject *args)
   double *dos;
   int* mesh;
   double* freq_points;
-  int num_freq_points;
   double* frequencies;
   double* coef;
   int (*grid_address)[3];
-  size_t num_gp, num_ir_gp;
-  int num_coef;
-  int num_band;
+  size_t num_gp, num_ir_gp, num_band, num_freq_points, num_coef;
   size_t *grid_mapping_table;
   int (*relative_grid_address)[4][3];
 
@@ -1403,12 +1397,12 @@ static PyObject * py_tetrahedron_method_dos(PyObject *self, PyObject *args)
   dos = (double*)PyArray_DATA(py_dos);
   mesh = (int*)PyArray_DATA(py_mesh);
   freq_points = (double*)PyArray_DATA(py_freq_points);
-  num_freq_points = (int)PyArray_DIMS(py_freq_points)[0];
+  num_freq_points = (size_t)PyArray_DIMS(py_freq_points)[0];
   frequencies = (double*)PyArray_DATA(py_frequencies);
   num_ir_gp = (size_t)PyArray_DIMS(py_frequencies)[0];
-  num_band = (int)PyArray_DIMS(py_frequencies)[1];
+  num_band = (size_t)PyArray_DIMS(py_frequencies)[1];
   coef = (double*)PyArray_DATA(py_coef);
-  num_coef = (int)PyArray_DIMS(py_coef)[1];
+  num_coef = (size_t)PyArray_DIMS(py_coef)[1];
   grid_address = (int(*)[3])PyArray_DATA(py_grid_address);
   num_gp = (size_t)PyArray_DIMS(py_grid_address)[0];
   grid_mapping_table = (size_t*)PyArray_DATA(py_grid_mapping_table);
diff --git a/c/kspclib/tetrahedron_method.c b/c/kspclib/tetrahedron_method.c
index 4258adb4..3430a8df 100644
--- a/c/kspclib/tetrahedron_method.c
+++ b/c/kspclib/tetrahedron_method.c
@@ -403,7 +403,8 @@ thm_get_dense_neighboring_grid_points(size_t neighboring_grid_points[],
                                       const size_t bz_map[])
 {
   int bzmesh[3], address_double[3], bz_address_double[3];
-  size_t i, j, bz_gp, prod_bz_mesh;
+  int i;
+  size_t j, bz_gp, prod_bz_mesh;
 
   prod_bz_mesh = 1;
   for (i = 0; i < 3; i++) {
diff --git a/phonopy/file_IO.py b/phonopy/file_IO.py
index 06b77c93..2a2431dc 100644
--- a/phonopy/file_IO.py
+++ b/phonopy/file_IO.py
@@ -533,7 +533,13 @@ def get_cell_from_disp_yaml(dataset):
             data_key = None
             pos_key = None
 
-        positions = [x[pos_key] for x in dataset[data_key]]
+        try:
+            positions = [x[pos_key] for x in dataset[data_key]]
+        except KeyError:
+            msg = ("\"disp.yaml\" format is too old. "
+                   "Please re-create it as \"phonopy_disp.yaml\" to contain "
+                   "supercell crystal structure information.")
+            raise RuntimeError(msg)
         symbols = [x['symbol'] for x in dataset[data_key]]
         cell = PhonopyAtoms(cell=lattice,
                             scaled_positions=positions,
diff --git a/phonopy/interface/calculator.py b/phonopy/interface/calculator.py
index 01224cb7..68017afb 100644
--- a/phonopy/interface/calculator.py
+++ b/phonopy/interface/calculator.py
@@ -345,16 +345,20 @@ def create_FORCE_SETS(interface_mode,
             print("NOTE:")
             print("  From phonopy v2.0, displacements are written into "
                   "\"phonopy_disp.yaml\".")
-            print("  \"disp.yaml\" is still supported for reading, but is "
-                  "deprecated.")
+            print("  \"disp.yaml\" is still supported for reading except for "
+                  "Wien2k interface, ")
+            print("  but is deprecated.")
             print('')
         if force_sets_zero_mode:
             print("Forces in %s are subtracted from forces in all "
                   "other files." % force_filenames[0])
 
     if disp_filename == 'disp.yaml':
-        disp_dataset, supercell = parse_disp_yaml(filename=disp_filename,
-                                                  return_cell=True)
+        if interface_mode == 'wein2k':
+            disp_dataset, supercell = parse_disp_yaml(filename=disp_filename,
+                                                      return_cell=True)
+        else:
+            disp_dataset = parse_disp_yaml(filename=disp_filename)
     else:
         phpy = PhonopyYaml()
         phpy.read(disp_filename)