diff --git a/kallithea/config/application.py b/kallithea/config/application.py
--- a/kallithea/config/application.py
+++ b/kallithea/config/application.py
@@ -20,6 +20,7 @@ from kallithea.config.middleware.simpleg
 from kallithea.config.middleware.simplehg import SimpleHg
 from kallithea.config.middleware.wrapper import RequestWrapper
 from kallithea.lib.utils2 import asbool
+from kallithea.lib.vcs.utils import hgcompat
 
 
 __all__ = ['make_app']
@@ -50,6 +51,7 @@ def wrap_app(app):
 def make_app(global_conf, **app_conf):
     """Return WSGI app with logging Mercurial stdout/stderr - to be used as
     Paste or mod_wsgi entry point"""
+    hgcompat.redirect_stdio_to_logging()
     return make_app_raw(global_conf, **app_conf)
 
 
diff --git a/kallithea/lib/vcs/utils/hgcompat.py b/kallithea/lib/vcs/utils/hgcompat.py
--- a/kallithea/lib/vcs/utils/hgcompat.py
+++ b/kallithea/lib/vcs/utils/hgcompat.py
@@ -2,10 +2,25 @@
 Mercurial libs compatibility
 """
 
+import logging
+
 import mercurial.encoding
 import mercurial.localrepo
 
 
+class MercurialStdLogger:
+    def __init__(self, logger):
+        self.logger = logger
+
+    def write(self, message):
+        try:
+            self.logger(message.decode().rstrip())
+        except:
+            self.logger(message)
+
+    def flush(self):
+        pass
+
 def monkey_do():
     """Apply some Mercurial monkey patching"""
     # workaround for 3.3 94ac64bcf6fe and not calling largefiles reposetup correctly, and test_archival failing
@@ -15,3 +30,18 @@ def monkey_do():
 
     # Minimize potential impact from custom configuration
     mercurial.encoding.environ[b'HGPLAIN'] = b'1'
+
+
+hglog = logging.getLogger("mercurial")
+
+
+def redirect_stdio_to_logging():
+    # Capture Mercurial stdout/stderr and send to a 'mercurial' logger
+    try:
+        import mercurial.utils.procutil as procutil
+        if not isinstance(procutil.stdout, MercurialStdLogger):
+            procutil.stdout = MercurialStdLogger(hglog.info)
+        if not isinstance(procutil.stderr, MercurialStdLogger):
+            procutil.stderr = MercurialStdLogger(hglog.warning)
+    except Exception as e:
+        hglog.error("Exception installing procutil stdout/stderr: %s", e)