diff --git a/jupytext/quarto.py b/jupytext/quarto.py
index 8692f0820..47cb4d175 100644
--- a/jupytext/quarto.py
+++ b/jupytext/quarto.py
@@ -22,12 +22,13 @@ def quarto(args, filein=None):
     if filein:
         cmd.append(filein)
 
-    proc = subprocess.Popen(cmd, stdout=subprocess.PIPE)
+    proc = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
     out, err = proc.communicate()
     if proc.returncode:
         raise QuartoError(
-            f"{' '.join(cmd)} exited with return code {proc.returncode}\n{err}"
+            f"{' '.join(cmd)} exited with return code {proc.returncode}\n{err.decode('utf-8')}"
         )
+
     return out.decode("utf-8")