diff --git a/requirements.txt b/requirements.txt
index 1fc8397..dd6b0e6 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,5 +1,5 @@
-Django>=3.1,<4.0
-tabimport>=0.4.0
+Django>=3.2<4.1
+tabimport==0.5.1
 xlrd<2  # Required by tabimport
 openpyxl==3.0.5
 reportlab
diff --git a/stages/views/imports.py b/stages/views/imports.py
index 304ba6e..fd855ca 100644
--- a/stages/views/imports.py
+++ b/stages/views/imports.py
@@ -188,7 +188,7 @@ class StudentImportView(ImportViewBase):
 
         for line in up_file:
             student_defaults = {
-                val: strip(line.get(key, '')) for key, val in self.student_mapping.items()
+                val: '' if line[key] is None else strip(line[key]) for key, val in self.student_mapping.items()
             }
             if student_defaults['ext_id'] in seen_students_ids:
                 # Second line for student, ignore it
@@ -200,7 +200,7 @@ class StudentImportView(ImportViewBase):
 
             if self.corporation_mapping:
                 corporation_defaults = {
-                    val: strip(line[key]) for key, val in self.corporation_mapping.items()
+                    val: '' if line[key] is None else strip(line[key]) for key, val in self.corporation_mapping.items()
                 }
                 if isinstance(corporation_defaults['pcode'], float):
                     corporation_defaults['pcode'] = int(corporation_defaults['pcode'])
@@ -271,7 +271,7 @@ class StudentImportView(ImportViewBase):
     def get_corporation(self, corp_values):
         if corp_values['ext_id'] == '':
             return None
-        if 'city' in corp_values and is_int(corp_values['city'][:4]):
+        if corp_values.get('city') and is_int(corp_values['city'][:4]):
             corp_values['pcode'], _, corp_values['city'] = corp_values['city'].partition(' ')
         try:
             corp, created = Corporation.objects.get_or_create(