diff --git a/langchain/chat_models/base.py b/langchain/chat_models/base.py
index fc77993de11..744037944ee 100644
--- a/langchain/chat_models/base.py
+++ b/langchain/chat_models/base.py
@@ -82,7 +82,9 @@ class BaseChatModel(BaseLanguageModel, ABC):
         )
         try:
             results = [
-                self._generate(m, stop=stop, run_manager=run_managers[0])
+                self._generate(
+                    m, stop=stop, run_manager=run_managers[0] if run_managers else None
+                )
                 if new_arg_supported
                 else self._generate(m, stop=stop)
                 for m in messages
@@ -126,7 +128,11 @@ class BaseChatModel(BaseLanguageModel, ABC):
         try:
             results = await asyncio.gather(
                 *[
-                    self._agenerate(m, stop=stop, run_manager=run_managers[0])
+                    self._agenerate(
+                        m,
+                        stop=stop,
+                        run_manager=run_managers[0] if run_managers else None,
+                    )
                     if new_arg_supported
                     else self._agenerate(m, stop=stop)
                     for m in messages
diff --git a/langchain/llms/base.py b/langchain/llms/base.py
index 95a1775cbe1..b6efa5e8a17 100644
--- a/langchain/llms/base.py
+++ b/langchain/llms/base.py
@@ -184,7 +184,11 @@ class BaseLLM(BaseLanguageModel, ABC):
             )
             try:
                 output = (
-                    self._generate(prompts, stop=stop, run_manager=run_managers[0])
+                    self._generate(
+                        prompts,
+                        stop=stop,
+                        run_manager=run_managers[0] if run_managers else None,
+                    )
                     if new_arg_supported
                     else self._generate(prompts, stop=stop)
                 )
@@ -209,7 +213,9 @@ class BaseLLM(BaseLanguageModel, ABC):
             try:
                 new_results = (
                     self._generate(
-                        missing_prompts, stop=stop, run_manager=run_managers[0]
+                        missing_prompts,
+                        stop=stop,
+                        run_manager=run_managers[0] if run_managers else None,
                     )
                     if new_arg_supported
                     else self._generate(missing_prompts, stop=stop)