diff --git a/faststream/specification/asyncapi/v2_6_0/generate.py b/faststream/specification/asyncapi/v2_6_0/generate.py
index 3882ae0a11..aa56d9582a 100644
--- a/faststream/specification/asyncapi/v2_6_0/generate.py
+++ b/faststream/specification/asyncapi/v2_6_0/generate.py
@@ -150,16 +150,25 @@ def get_broker_channels(
     channels = {}
 
     for h in broker._subscribers:
-        # TODO: add duplication key warning
-        channels.update({
-            key: Channel.from_sub(channel) for key, channel in h.schema().items()
-        })
-
+        for key, channel in h.schema().items():
+            if key in channels:
+                warnings.warn(
+                    f"Overwrite channel handler, channels have the same names: `{key}`",
+                    RuntimeWarning,
+                    stacklevel=1,
+                )
+            channels[key] = Channel.from_sub(channel)
+             
     for p in broker._publishers:
-        # TODO: add duplication key warning
-        channels.update({
-            key: Channel.from_pub(channel) for key, channel in p.schema().items()
-        })
+        for key, channel in p.schema().items():
+            if key in channels:
+                warnings.warn(
+                    f"Overwrite channel handler, channels have the same names: `{key}`",
+                    RuntimeWarning,
+                    stacklevel=1,
+                )
+
+            channels[key] = Channel.from_pub(channel)
 
     return channels
 
diff --git a/faststream/specification/asyncapi/v3_0_0/generate.py b/faststream/specification/asyncapi/v3_0_0/generate.py
index 3c4aec1051..0ef22bf909 100644
--- a/faststream/specification/asyncapi/v3_0_0/generate.py
+++ b/faststream/specification/asyncapi/v3_0_0/generate.py
@@ -158,7 +158,13 @@ def get_broker_channels(
             channel_obj = Channel.from_sub(sub_key, sub_channel)
 
             channel_key = clear_key(sub_key)
-            # TODO: add duplication key warning
+            if channel_key in channels:
+                warnings.warn(
+                    f"Overwrite channel handler, channels have the same names: `{channel_key}`",
+                    RuntimeWarning,
+                    stacklevel=1,
+                )
+
             channels[channel_key] = channel_obj
 
             operations[f"{channel_key}Subscribe"] = Operation.from_sub(
@@ -177,7 +183,12 @@ def get_broker_channels(
             channel_obj = Channel.from_pub(pub_key, pub_channel)
 
             channel_key = clear_key(pub_key)
-            # TODO: add duplication key warning
+            if channel_key in channels:
+                warnings.warn(
+                    f"Overwrite channel handler, channels have the same names: `{channel_key}`",
+                    RuntimeWarning,
+                    stacklevel=1,
+                )
             channels[channel_key] = channel_obj
 
             operations[channel_key] = Operation.from_pub(