diff --git a/litellm/constants.py b/litellm/constants.py
index b1a0021bcc6..d34c369e4cf 100644
--- a/litellm/constants.py
+++ b/litellm/constants.py
@@ -49,6 +49,14 @@ DEFAULT_REPLICATE_POLLING_DELAY_SECONDS = int(
 )
 DEFAULT_IMAGE_TOKEN_COUNT = int(os.getenv("DEFAULT_IMAGE_TOKEN_COUNT", 250))
 
+# Maximum wall-clock seconds a streaming response is allowed to run.
+# Streams exceeding this duration are terminated with a Timeout error.
+# None (default) = no limit.  Set env var to a number of seconds to enable globally.
+_max_stream_duration_env = os.getenv("LITELLM_MAX_STREAMING_DURATION_SECONDS", None)
+MAX_STREAMING_CHUNK_DURATION_S = (
+    float(_max_stream_duration_env) if _max_stream_duration_env is not None else None
+)
+
 # Maximum number of base64 characters to keep in logging payloads.
 # Data URIs exceeding this are replaced with a size placeholder.
 # Set to 0 to disable truncation.