diff --git a/run_agent.py b/run_agent.py
index a3a2b6d58..8b53d030c 100644
--- a/run_agent.py
+++ b/run_agent.py
@@ -6640,11 +6640,15 @@ class AIAgent:
             # Without this, compression decisions use the primary model's
             # context window (e.g. 200K) instead of the fallback's (e.g. 32K),
             # causing oversized sessions to overflow the fallback.
+            # Also pass _config_context_length so the explicit config override
+            # (model.context_length in config.yaml) is respected — without this,
+            # the fallback activation drops to 128K even when config says 204800.
             if hasattr(self, 'context_compressor') and self.context_compressor:
                 from agent.model_metadata import get_model_context_length
                 fb_context_length = get_model_context_length(
                     self.model, base_url=self.base_url,
                     api_key=self.api_key, provider=self.provider,
+                    config_context_length=getattr(self, "_config_context_length", None),
                 )
                 self.context_compressor.update_model(
                     model=self.model,