diff --git a/claude_sonnet-3-7-bedrock.py b/claude_sonnet-3-7-bedrock.py
index d1761a8..13f70d5 100644
--- a/claude_sonnet-3-7-bedrock.py
+++ b/claude_sonnet-3-7-bedrock.py
@@ -189,7 +189,7 @@ class Pipeline:
                     yield '<thinking>\n' 
                   yield delta["reasoningContent"]["text"]
 
-                if "contentBlockStop" in delta and delta["contentBlockStop"]["contentBlockIndex"] == thinking_block:
+                if "contentBlockStop" in chunk and chunk["contentBlockStop"]["contentBlockIndex"] == thinking_block:
                   yield '</thinking>\n\n'
 
                 # Handle regular response text