diff --git a/src/anthropic/_base_client.py b/src/anthropic/_base_client.py
index c77bb55df..db4c36de7 100644
--- a/src/anthropic/_base_client.py
+++ b/src/anthropic/_base_client.py
@@ -733,7 +733,7 @@ def _calculate_nonstreaming_timeout(self, max_tokens: int, max_nonstreaming_toke
         default_time = 60 * 10
 
         expected_time = maximum_time * max_tokens / 128_000
-        if expected_time > default_time or (max_nonstreaming_tokens and max_tokens > max_nonstreaming_tokens):
+        if expected_time > default_time or (max_nonstreaming_tokens is not None and max_tokens > max_nonstreaming_tokens):
             raise ValueError(
                 "Streaming is required for operations that may take longer than 10 minutes. "
                 + "See https://github.com/anthropics/anthropic-sdk-python#long-requests for more details",