diff --git a/trytond/model/modelstorage.py b/trytond/model/modelstorage.py
index 4947ad43bc..40772807c1 100644
--- a/trytond/model/modelstorage.py
+++ b/trytond/model/modelstorage.py
@@ -859,11 +859,26 @@ class ModelStorage(Model):
                         else:
                             res = bool(int(value))
                     elif field_type == 'integer':
-                        res = int(value) if value else None
+                        if isinstance(value, int):
+                            res = value
+                        elif value:
+                            res = int(value)
+                        else:
+                            res = None
                     elif field_type == 'float':
-                        res = float(value) if value else None
+                        if isinstance(value, float):
+                            res = value
+                        elif value:
+                            res = float(value)
+                        else:
+                            res = None
                     elif field_type == 'numeric':
-                        res = Decimal(value) if value else None
+                        if isinstance(value, Decimal):
+                            res = value
+                        elif value:
+                            res = Decimal(value)
+                        else:
+                            res = None
                     elif field_type == 'date':
                         if isinstance(value, datetime.date):
                             res = value
diff --git a/trytond/tests/test_importdata.py b/trytond/tests/test_importdata.py
index bff8307f85..f05f25355d 100644
--- a/trytond/tests/test_importdata.py
+++ b/trytond/tests/test_importdata.py
@@ -55,6 +55,9 @@ class ImportDataTestCase(unittest.TestCase):
         self.assertEqual(Integer.import_data(['integer'],
             [['1']]), 1)
 
+        self.assertEqual(Integer.import_data(['integer'],
+            [[0]]), 1)
+
         self.assertEqual(Integer.import_data(['integer'],
             [[1]]), 1)
 
@@ -79,6 +82,9 @@ class ImportDataTestCase(unittest.TestCase):
         self.assertEqual(Integer.import_data(['integer'],
             [['0']]), 1)
 
+        self.assertEqual(Integer.import_data(['integer'],
+            [[None]]), 1)
+
     @with_transaction()
     def test_integer_required(self):
         'Test required integer'
@@ -111,6 +117,13 @@ class ImportDataTestCase(unittest.TestCase):
         self.assertEqual(IntegerRequired.import_data(['integer'],
             [['0']]), 1)
 
+        self.assertEqual(IntegerRequired.import_data(['integer'],
+            [[0]]), 1)
+
+        with self.assertRaises(RequiredValidationError):
+            IntegerRequired.import_data(['integer'], [[None]])
+        transaction.rollback()
+
     @with_transaction()
     def test_float(self):
         'Test float'
@@ -120,6 +133,9 @@ class ImportDataTestCase(unittest.TestCase):
         self.assertEqual(Float.import_data(['float'],
             [['1.1']]), 1)
 
+        self.assertEqual(Float.import_data(['float'],
+            [[0.0]]), 1)
+
         self.assertEqual(Float.import_data(['float'],
             [[1.1]]), 1)
 
@@ -144,6 +160,9 @@ class ImportDataTestCase(unittest.TestCase):
         self.assertEqual(Float.import_data(['float'],
             [['0.0']]), 1)
 
+        self.assertEqual(Float.import_data(['float'],
+            [[None]]), 1)
+
     @with_transaction()
     def test_float_required(self):
         'Test required float'
@@ -176,6 +195,13 @@ class ImportDataTestCase(unittest.TestCase):
         self.assertEqual(FloatRequired.import_data(['float'],
             [['0.0']]), 1)
 
+        self.assertEqual(FloatRequired.import_data(['float'],
+            [[0.0]]), 1)
+
+        with self.assertRaises(RequiredValidationError):
+            FloatRequired.import_data(['float'], [[None]])
+        transaction.rollback()
+
     @with_transaction()
     def test_numeric(self):
         'Test numeric'
@@ -185,6 +211,9 @@ class ImportDataTestCase(unittest.TestCase):
         self.assertEqual(Numeric.import_data(['numeric'],
             [['1.1']]), 1)
 
+        self.assertEqual(Numeric.import_data(['numeric'],
+            [[Decimal('0.0')]]), 1)
+
         self.assertEqual(Numeric.import_data(['numeric'],
             [[Decimal('1.1')]]), 1)
 
@@ -209,6 +238,9 @@ class ImportDataTestCase(unittest.TestCase):
         self.assertEqual(Numeric.import_data(['numeric'],
             [['0.0']]), 1)
 
+        self.assertEqual(Numeric.import_data(['numeric'],
+            [[None]]), 1)
+
     @with_transaction()
     def test_numeric_required(self):
         'Test required numeric'
@@ -241,6 +273,13 @@ class ImportDataTestCase(unittest.TestCase):
         self.assertEqual(NumericRequired.import_data(['numeric'],
             [['0.0']]), 1)
 
+        self.assertEqual(NumericRequired.import_data(['numeric'],
+            [[Decimal('0.0')]]), 1)
+
+        with self.assertRaises(RequiredValidationError):
+            NumericRequired.import_data(['numeric'], [[None]])
+        transaction.rollback()
+
     @with_transaction()
     def test_char(self):
         'Test char'