diff --git a/src/pyfmi/fmi.pyx b/src/pyfmi/fmi.pyx
index 79b7aa36..36da6c0a 100644
--- a/src/pyfmi/fmi.pyx
+++ b/src/pyfmi/fmi.pyx
@@ -5098,7 +5098,7 @@ cdef class FMUModelBase2(ModelBase):
             filter_list = self._convert_filter(filter)
             length_filter = len(filter_list)
 
-        for i in range(<int>variable_list_size):
+        for i in range(<size_t>variable_list_size):
 
             variable = FMIL.fmi2_import_get_variable(variable_list, i)
 
@@ -5227,7 +5227,7 @@ cdef class FMUModelBase2(ModelBase):
             filter_list = self._convert_filter(filter)
             length_filter = len(filter_list)
 
-        for i in range(<int>variable_list_size):
+        for i in range(<size_t>variable_list_size):
 
             variable = FMIL.fmi2_import_get_variable(variable_list, i)
 
@@ -7213,7 +7213,7 @@ cdef class FMUModelCS2(FMUModelBase2):
             value_refs[0] = self.get_variable_valueref(variables)
         elif isinstance(variables,list) and N.prod([int(isinstance(v,str)) for v in variables]): #prod equals 0 or 1
             value_refs = N.array([0]*<size_t>nref, dtype=N.uint32,ndmin=1).ravel()
-            for i in range(<int>nref):
+            for i in range(<size_t>nref):
                 value_refs[i] = self.get_variable_valueref(variables[i])
                 orders[i] = order
         else:
@@ -7279,7 +7279,7 @@ cdef class FMUModelCS2(FMUModelBase2):
             nref = len(variables)
             value_refs = N.array([0]*<size_t>nref, dtype=N.uint32, ndmin=1).ravel()
             orders = N.array([0]*<size_t>nref, dtype=N.int32)
-            for i in range(<int>nref):
+            for i in range(<size_t>nref):
                 value_refs[i] = self.get_variable_valueref(variables[i])
                 orders[i] = order
         else:
diff --git a/src/pyfmi/fmi_extended.pyx b/src/pyfmi/fmi_extended.pyx
index 01ee7045..e0fa9407 100644
--- a/src/pyfmi/fmi_extended.pyx
+++ b/src/pyfmi/fmi_extended.pyx
@@ -293,9 +293,9 @@ cdef class FMUModelME1Extended(FMUModelME1):
         cdef N.ndarray[FMIL.fmi1_real_t, ndim=1,mode='c'] val = N.array(values, dtype=float, ndmin=1).flatten()
 
         nref = len(val)
-        orders = N.array([0]*nref, dtype=N.int32)
+        orders = N.array([0]*<size_t>nref, dtype=N.int32)
 
-        if nref != len(np_orders):
+        if <size_t>nref != len(np_orders):
             raise FMUException("The number of variables must be the same as the number of orders.")
 
         for i in range(len(np_orders)):
@@ -308,13 +308,13 @@ cdef class FMUModelME1Extended(FMUModelME1):
             value_refs = N.array([0], dtype=N.uint32,ndmin=1).flatten()
             value_refs[0] = self.get_variable_valueref(variables)
         elif isinstance(variables,list) and isinstance(variables[-1],str):
-            value_refs = N.array([0]*nref, dtype=N.uint32,ndmin=1).flatten()
-            for i in range(nref):
+            value_refs = N.array([0]*<size_t>nref, dtype=N.uint32,ndmin=1).flatten()
+            for i in range(<size_t>nref):
                 value_refs[i] = self.get_variable_valueref(variables[i])
         else:
             raise FMUException("The variables must either be a string or a list of strings")
         
-        for i in range(nref):
+        for i in range(<size_t>nref):
             self._input_derivatives[value_refs[i]][np_orders[i]-1] = val[i]/self._input_factorials[np_orders[i]-1]
             
         #Activate input
diff --git a/src/pyfmi/fmi_util.pyx b/src/pyfmi/fmi_util.pyx
index c98bbf8c..c5186d6e 100644
--- a/src/pyfmi/fmi_util.pyx
+++ b/src/pyfmi/fmi_util.pyx
@@ -1105,11 +1105,14 @@ cdef class DumpData:
             self.dump_data(np.array(float(self.model.time)))
         self.dump_data(diag_data)
 
-from libc.stdio cimport *
+# from libc.stdio cimport *
 
 cdef extern from "stdio.h":
     FILE *fdopen(int, const char *)
-
+    FILE *fopen(const char *, const char *)
+    size_t fread(void*, size_t, size_t, FILE *)
+    int fseek(FILE *, long, int)
+    int fclose(FILE *)
 
 @cython.boundscheck(False)
 @cython.wraparound(False)
diff --git a/src/pyfmi/master.pyx b/src/pyfmi/master.pyx
index 4e1e5f2f..b68ec993 100644
--- a/src/pyfmi/master.pyx
+++ b/src/pyfmi/master.pyx
@@ -87,8 +87,9 @@ cdef perform_do_step_parallel(list models, FMIL.fmi2_import_t** model_addresses,
     Perform a do step on all the models.
     """
     cdef int i, status = 0
-    cdef int num_threads, id
-    cdef double time
+    cdef int num_threads
+    # cdef int id
+    # cdef double time
     
     for i in prange(n, nogil=True, schedule="dynamic", chunksize=1): 
     #for i in prange(n, nogil=True, schedule="dynamic"):