diff --git a/wsme/rest/args.py b/wsme/rest/args.py
index 4574cdd..9b8f2e1 100644
--- a/wsme/rest/args.py
+++ b/wsme/rest/args.py
@@ -18,7 +18,7 @@ ARRAY_MAX_SIZE = 1000
 
 @generic
 def from_param(datatype, value):
-    return datatype(value) if value else None
+    return datatype(value) if value is not None else None
 
 
 @from_param.when_object(datetime.date)
diff --git a/wsme/tests/test_protocols_commons.py b/wsme/tests/test_protocols_commons.py
index 19908b2..6a4c1a8 100644
--- a/wsme/tests/test_protocols_commons.py
+++ b/wsme/tests/test_protocols_commons.py
@@ -75,3 +75,32 @@ class TestProtocolsCommons(unittest.TestCase):
             assert fake_type.name in str(e)
         else:
             self.fail('Should have thrown an InvalidInput')
+
+
+class ArgTypeConversion(unittest.TestCase):
+
+    def test_int_zero(self):
+        self.assertEqual(0, from_param(int, 0))
+        self.assertEqual(0, from_param(int, '0'))
+
+    def test_int_nonzero(self):
+        self.assertEqual(1, from_param(int, 1))
+        self.assertEqual(1, from_param(int, '1'))
+
+    def test_int_none(self):
+        self.assertEqual(None, from_param(int, None))
+
+    def test_float_zero(self):
+        self.assertEqual(0.0, from_param(float, 0))
+        self.assertEqual(0.0, from_param(float, 0.0))
+        self.assertEqual(0.0, from_param(float, '0'))
+        self.assertEqual(0.0, from_param(float, '0.0'))
+
+    def test_float_nonzero(self):
+        self.assertEqual(1.0, from_param(float, 1))
+        self.assertEqual(1.0, from_param(float, 1.0))
+        self.assertEqual(1.0, from_param(float, '1'))
+        self.assertEqual(1.0, from_param(float, '1.0'))
+
+    def test_float_none(self):
+        self.assertEqual(None, from_param(float, None))