diff --git a/zerver/management/commands/runtusd.py b/zerver/management/commands/runtusd.py
index 9a660a7e2b..6d4630ba7a 100644
--- a/zerver/management/commands/runtusd.py
+++ b/zerver/management/commands/runtusd.py
@@ -63,6 +63,10 @@ class Command(BaseCommand):
                 env_vars["AWS_ACCESS_KEY_ID"] = settings.S3_KEY
             if settings.S3_SECRET_KEY is not None:
                 env_vars["AWS_SECRET_ACCESS_KEY"] = settings.S3_SECRET_KEY
-            assert settings.S3_REGION is not None
-            env_vars["AWS_REGION"] = settings.S3_REGION
+            if settings.S3_REGION is None:
+                import boto3
+
+                env_vars["AWS_REGION"] = boto3.client("s3").meta.region_name
+            else:
+                env_vars["AWS_REGION"] = settings.S3_REGION
         os.execvpe("tusd", tusd_args, env_vars)