diff --git a/lib/crewai/src/crewai/llm.py b/lib/crewai/src/crewai/llm.py
index 0b3b158d6..75b1f6546 100644
--- a/lib/crewai/src/crewai/llm.py
+++ b/lib/crewai/src/crewai/llm.py
@@ -483,8 +483,8 @@ class LLM(BaseLLM):
                 for prefix in ["gpt-", "gpt-35-", "o1", "o3", "o4", "azure-"]
             )
 
-        # OpenAI-compatible providers - accept any model name since these
-        # providers host many different models with varied naming conventions
+        # OpenAI-compatible providers - most accept any model name, but some
+        # (DeepSeek, Dashscope) restrict to their own model prefixes
         if provider == "deepseek":
             return model_lower.startswith("deepseek")
 
diff --git a/lib/crewai/src/crewai/llms/providers/openai_compatible/completion.py b/lib/crewai/src/crewai/llms/providers/openai_compatible/completion.py
index 9c308f52e..293e73ff0 100644
--- a/lib/crewai/src/crewai/llms/providers/openai_compatible/completion.py
+++ b/lib/crewai/src/crewai/llms/providers/openai_compatible/completion.py
@@ -239,7 +239,8 @@ class OpenAICompatibleCompletion(OpenAICompletion):
         if base_url:
             resolved = base_url
         elif config.base_url_env:
-            resolved = os.getenv(config.base_url_env, config.base_url)
+            env_value = os.getenv(config.base_url_env)
+            resolved = env_value if env_value else config.base_url
         else:
             resolved = config.base_url
 
@@ -274,9 +275,11 @@ class OpenAICompatibleCompletion(OpenAICompletion):
     def supports_function_calling(self) -> bool:
         """Check if the provider supports function calling.
 
-        All modern OpenAI-compatible providers support function calling.
+        Delegates to the parent OpenAI implementation which handles
+        edge cases like o1 models (which may be routed through
+        OpenRouter or other compatible providers).
 
         Returns:
-            True, as all supported providers have function calling support.
+            Whether the model supports function calling.
         """
-        return True
+        return super().supports_function_calling()
diff --git a/lib/crewai/tests/llms/openai_compatible/test_openai_compatible.py b/lib/crewai/tests/llms/openai_compatible/test_openai_compatible.py
index ade54fb8c..fd5970299 100644
--- a/lib/crewai/tests/llms/openai_compatible/test_openai_compatible.py
+++ b/lib/crewai/tests/llms/openai_compatible/test_openai_compatible.py
@@ -1,7 +1,7 @@
 """Tests for OpenAI-compatible providers."""
 
 import os
-from unittest.mock import MagicMock, patch
+from unittest.mock import patch
 
 import pytest
 
@@ -133,7 +133,7 @@ class TestOpenAICompatibleCompletion:
             with pytest.raises(ValueError, match="API key required"):
                 OpenAICompatibleCompletion(model="deepseek-chat", provider="deepseek")
         finally:
-            if original:
+            if original is not None:
                 os.environ[env_key] = original
 
     def test_api_key_from_env(self):