diff --git a/clearml/backend_api/config/default/api.conf b/clearml/backend_api/config/default/api.conf
index 10145862..277ea559 100644
--- a/clearml/backend_api/config/default/api.conf
+++ b/clearml/backend_api/config/default/api.conf
@@ -23,6 +23,11 @@
     http {
         max_req_size = 15728640  # request size limit (smaller than that configured in api server)
 
+        # extra retry codes on which the session will automatically use the specified retry.
+        # these will be added to the default retry list which currently includes bad gateway (502),
+        # service unavailable (503), bandwidth limit exceeded (509) and too many requests (429)
+        extra_retry_codes: []
+
         retries {
             # retry values (int, 0 means fail on first retry)
             total: 240     # Total number of retries to allow. Takes precedence over other counts.
diff --git a/clearml/backend_api/session/defs.py b/clearml/backend_api/session/defs.py
index b553f838..e34da8ca 100644
--- a/clearml/backend_api/session/defs.py
+++ b/clearml/backend_api/session/defs.py
@@ -26,3 +26,11 @@ POST requests can be used instead.
 However this has not been vigorously tested and may have unintended consequences.
 """
 ENV_API_DEFAULT_REQ_METHOD = EnvEntry("CLEARML_API_DEFAULT_REQ_METHOD")
+
+"""
+Experimental option to make the SDK retry on additional error codes.
+Use a comma-separated list of integer return codes.
+NOTE: this changes behavior and might cause the experiment to wait 
+for a very long time for a non-responding or mis-configured server
+"""
+ENV_API_EXTRA_RETRY_CODES = EnvEntry("CLEARML_API_EXTRA_RETRY_CODES")
diff --git a/clearml/backend_api/session/session.py b/clearml/backend_api/session/session.py
index da9566bd..19dda1a2 100644
--- a/clearml/backend_api/session/session.py
+++ b/clearml/backend_api/session/session.py
@@ -9,6 +9,7 @@ import requests
 import six
 from requests.auth import HTTPBasicAuth
 from six.moves.urllib.parse import urlparse, urlunparse
+from typing import List
 
 from .callresult import CallResult
 from .defs import (
@@ -25,6 +26,7 @@ from .defs import (
     ENV_ENABLE_ENV_CONFIG_SECTION,
     ENV_ENABLE_FILES_CONFIG_SECTION,
     ENV_API_DEFAULT_REQ_METHOD,
+    ENV_API_EXTRA_RETRY_CODES,
 )
 from .request import Request, BatchRequest  # noqa: F401
 from .token_manager import TokenManager
@@ -183,7 +185,8 @@ class Session(TokenManager):
         self.__host = host.strip("/")
         http_retries_config = http_retries_config or self.config.get(
             "api.http.retries", ConfigTree()).as_plain_ordered_dict()
-        http_retries_config["status_forcelist"] = self._retry_codes
+
+        http_retries_config["status_forcelist"] = self._get_retry_codes()
         self.__http_session = get_http_session_with_retry(**http_retries_config)
         self.__http_session.write_timeout = self._write_session_timeout
         self.__http_session.request_size_threshold = self._write_session_data_size
@@ -233,6 +236,25 @@ class Session(TokenManager):
 
         self._apply_config_sections(local_logger)
 
+    def _get_retry_codes(self):
+        # type: () -> List[int]
+        retry_codes = set(self._retry_codes)
+
+        extra = self.config.get("api.http.extra_retry_codes", [])
+        if ENV_API_EXTRA_RETRY_CODES.get():
+            extra = [s.strip() for s in ENV_API_EXTRA_RETRY_CODES.get().split(",") if s.strip()]
+
+        for code in extra or []:
+            try:
+                retry_codes.add(int(code))
+            except (ValueError, TypeError):
+                print("Warning: invalid extra HTTP retry code detected: {}".format(code))
+
+        if retry_codes.difference(self._retry_codes):
+            print("Using extra HTTP retry codes {}".format(sorted(retry_codes.difference(self._retry_codes))))
+
+        return list(retry_codes)
+
     def _load_vaults(self):
         if not self.check_min_api_version("2.15") or self.feature_set == "basic":
             return