diff --git a/byml_to_yml b/byml_to_yml
index c0b7ab0..d6e0d90 100755
--- a/byml_to_yml
+++ b/byml_to_yml
@@ -33,7 +33,6 @@ with file:
     elif '!!' in args.yml:
         sys.stderr.write('error: cannot use !! (for input filename) when reading from stdin\n')
         sys.exit(1)
-    sys.stderr.write('writing to %s\n' % args.yml)
     output = sys.stdout if args.yml == '-' else open(args.yml, 'w')
     with output:
         yaml.dump(root, output, Dumper=dumper, allow_unicode=True)
diff --git a/yaz0_util.py b/yaz0_util.py
index 9e307c6..d2695a7 100644
--- a/yaz0_util.py
+++ b/yaz0_util.py
@@ -5,8 +5,8 @@
 
 def compress(data: bytes) -> bytes:
     return subprocess.run([_tool_name, "comp", "-", "-d-", "-C10"], input=data, stdout=subprocess.PIPE,
-        check=True).stdout
+        stderr=subprocess.PIPE, check=True).stdout
 
 def decompress(data: bytes) -> bytes:
     return subprocess.run([_tool_name, "de", "-", "-d-"], input=data, stdout=subprocess.PIPE,
-        check=True).stdout
+        stderr=subprocess.PIPE, check=True).stdout
diff --git a/yml_to_byml b/yml_to_byml
index f649bb6..7537fd6 100755
--- a/yml_to_byml
+++ b/yml_to_byml
@@ -41,10 +41,8 @@ with file:
     if args.byml != '-':
         extension = os.path.splitext(args.byml)[1]
         if extension.startswith('.s'):
-            sys.stderr.write('compressing sbyml\n')
             buf = io.BytesIO(yaz0_util.compress(buf.read()))
 
-    sys.stderr.write('writing to %s\n' % args.byml)
     output = sys.stdout.buffer if args.byml == '-' else open(args.byml, 'wb')
     with output:
         shutil.copyfileobj(buf, output)