diff --git a/draw/viewport.py b/draw/viewport.py
index b74f270e..d5d881b9 100644
--- a/draw/viewport.py
+++ b/draw/viewport.py
@@ -200,7 +200,11 @@ def start_denoiser(self, luxcore_session):
             "-nrm", self._normal_file_path,
             "-o", self._denoised_file_path,
         ]
-        self._denoiser_process = subprocess.Popen(args)
+        self._denoiser_process = subprocess.Popen(
+            args,
+            stdout=subprocess.PIPE,
+            stderr=subprocess.PIPE,
+        )
 
     def is_denoiser_active(self):
         return self._denoiser_process is not None