diff --git a/pyotb/core.py b/pyotb/core.py
index 9cd9d4eeff26ce85ccd1eb63ffef30b3445e3935..0b0124910224864e8d06d2b100cf3722fc55470f 100644
--- a/pyotb/core.py
+++ b/pyotb/core.py
@@ -764,7 +764,7 @@ class App(OTBObject):
             dtype: data type to use
 
         """
-        if not dtype:
+        if dtype is None:
             param = self._settings.get(self.input_image_key)
             if not param:
                 logger.warning(
diff --git a/tests/test_core.py b/tests/test_core.py
index 8b3f8fae5fbe66124ceb3c6911e09aca11ba010b..a84d5eb2965eb7291d31c8ff52e7105cbf812cc0 100644
--- a/tests/test_core.py
+++ b/tests/test_core.py
@@ -1,6 +1,7 @@
 import pytest
 import numpy as np
 
+import pyotb
 from tests_data import *
 
 
@@ -144,11 +145,17 @@ def test_xy_to_rowcol():
 
 
 def test_write():
-    assert INPUT.write("/dev/shm/test_write.tif", ext_fname="nodata=0")
+    # Write string filepath
+    assert INPUT.write("/dev/shm/test_write.tif")
+    INPUT["out"].filepath.unlink()
+    # With Path filepath
+    assert INPUT.write(Path("/dev/shm/test_write.tif"))
     INPUT["out"].filepath.unlink()
-    assert INPUT.write(Path("/dev/shm/test_write.tif"), ext_fname="nodata=0")
+    # Write to uint8
+    assert INPUT.write(Path("/dev/shm/test_write.tif"), pixel_type="uint8")
+    assert INPUT["out"].dtype == "uint8"
     INPUT["out"].filepath.unlink()
-    # Frozen
+    # Write frozen app
     frozen_app = pyotb.BandMath(INPUT, exp="im1b1", frozen=True)
     assert frozen_app.write("/dev/shm/test_frozen_app_write.tif")
     frozen_app["out"].filepath.unlink()