diff --git a/async_substrate_interface/async_substrate.py b/async_substrate_interface/async_substrate.py
index c555c7b..25b6791 100644
--- a/async_substrate_interface/async_substrate.py
+++ b/async_substrate_interface/async_substrate.py
@@ -3987,6 +3987,32 @@ async def result_handler(message: dict, subscription_id) -> tuple[dict, bool]:
                 message_result = {
                     k.lower(): v for k, v in message["params"]["result"].items()
                 }
+                # check for any subscription indicators of failure
+                failure_message = None
+                if "usurped" in message_result:
+                    failure_message = (
+                        f"Subscription {subscription_id} usurped: {message_result}"
+                    )
+                if "retracted" in message_result:
+                    failure_message = (
+                        f"Subscription {subscription_id} retracted: {message_result}"
+                    )
+                if "finalitytimeout" in message_result:
+                    failure_message = f"Subscription {subscription_id} finalityTimeout: {message_result}"
+                if "dropped" in message_result:
+                    failure_message = (
+                        f"Subscription {subscription_id} dropped: {message_result}"
+                    )
+                if "invalid" in message_result:
+                    failure_message = (
+                        f"Subscription {subscription_id} invalid: {message_result}"
+                    )
+
+                if failure_message is not None:
+                    async with self.ws as ws:
+                        await ws.unsubscribe(subscription_id)
+                    logger.error(failure_message)
+                    raise SubstrateRequestException(failure_message)
 
                 if "finalized" in message_result and wait_for_finalization:
                     logger.debug("Extrinsic finalized. Unsubscribing.")
@@ -3998,7 +4024,7 @@ async def result_handler(message: dict, subscription_id) -> tuple[dict, bool]:
                         "finalized": True,
                     }, True
                 elif (
-                    any(x in message_result for x in ["inblock", "inBlock"])
+                    "inblock" in message_result
                     and wait_for_inclusion
                     and not wait_for_finalization
                 ):
diff --git a/async_substrate_interface/sync_substrate.py b/async_substrate_interface/sync_substrate.py
index c175c1f..a6c0be0 100644
--- a/async_substrate_interface/sync_substrate.py
+++ b/async_substrate_interface/sync_substrate.py
@@ -3170,6 +3170,32 @@ def result_handler(message: dict, subscription_id) -> tuple[dict, bool]:
                     k.lower(): v for k, v in message["params"]["result"].items()
                 }
 
+                # check for any subscription indicators of failure
+                failure_message = None
+                if "usurped" in message_result:
+                    failure_message = (
+                        f"Subscription {subscription_id} usurped: {message_result}"
+                    )
+                if "retracted" in message_result:
+                    failure_message = (
+                        f"Subscription {subscription_id} retracted: {message_result}"
+                    )
+                if "finalitytimeout" in message_result:
+                    failure_message = f"Subscription {subscription_id} finalityTimeout: {message_result}"
+                if "dropped" in message_result:
+                    failure_message = (
+                        f"Subscription {subscription_id} dropped: {message_result}"
+                    )
+                if "invalid" in message_result:
+                    failure_message = (
+                        f"Subscription {subscription_id} invalid: {message_result}"
+                    )
+
+                if failure_message is not None:
+                    self.rpc_request("author_unwatchExtrinsic", [subscription_id])
+                    logger.error(failure_message)
+                    raise SubstrateRequestException(failure_message)
+
                 if "finalized" in message_result and wait_for_finalization:
                     # Created as a task because we don't actually care about the result
                     # TODO change this logic