diff --git a/libs/langchain/langchain/schema/runnable/base.py b/libs/langchain/langchain/schema/runnable/base.py
index 9968595677f..803143df6ad 100644
--- a/libs/langchain/langchain/schema/runnable/base.py
+++ b/libs/langchain/langchain/schema/runnable/base.py
@@ -2425,7 +2425,11 @@ class RunnableBinding(RunnableSerializable[Input, Output]):
 
     def bind(self, **kwargs: Any) -> Runnable[Input, Output]:
         return self.__class__(
-            bound=self.bound, config=self.config, kwargs={**self.kwargs, **kwargs}
+            bound=self.bound,
+            config=self.config,
+            kwargs={**self.kwargs, **kwargs},
+            custom_input_type=self.custom_input_type,
+            custom_output_type=self.custom_output_type,
         )
 
     def with_config(
@@ -2438,6 +2442,8 @@ class RunnableBinding(RunnableSerializable[Input, Output]):
             bound=self.bound,
             kwargs=self.kwargs,
             config=cast(RunnableConfig, {**self.config, **(config or {}), **kwargs}),
+            custom_input_type=self.custom_input_type,
+            custom_output_type=self.custom_output_type,
         )
 
     def with_types(