diff --git a/bittensor/core/async_subtensor.py b/bittensor/core/async_subtensor.py
index ca90ba4299..ea7ec359bb 100644
--- a/bittensor/core/async_subtensor.py
+++ b/bittensor/core/async_subtensor.py
@@ -343,7 +343,7 @@ async def determine_block_hash(
         # Return the appropriate value.
         if block_hash:
             return block_hash
-        if block:
+        if block is not None:
             return await self.get_block_hash(block)
         return None
 
@@ -1235,6 +1235,9 @@ async def get_balances(
         """
         if reuse_block:
             block_hash = self.substrate.last_block_hash
+        elif block_hash is None and block is None:
+            # Neither block nor block_hash provided, default to head
+            block_hash = await self.get_block_hash()
         else:
             block_hash = await self.determine_block_hash(block, block_hash, reuse_block)
         calls = [
@@ -1306,7 +1309,7 @@ async def get_block_hash(self, block: Optional[int] = None) -> str:
         Notes:
             See also: <https://docs.learnbittensor.org/glossary#block>
         """
-        if block:
+        if block is not None:
             return await self._get_block_hash(block)
         else:
             return await self.substrate.get_chain_head()
diff --git a/bittensor/core/subtensor.py b/bittensor/core/subtensor.py
index 28371fb7d6..49729d6a8b 100644
--- a/bittensor/core/subtensor.py
+++ b/bittensor/core/subtensor.py
@@ -746,7 +746,7 @@ def get_block_hash(self, block: Optional[int] = None) -> str:
             data. It is crucial for verifying transactions, ensuring data consistency, and maintaining the
             trustworthiness of the blockchain.
         """
-        if block:
+        if block is not None:
             return self._get_block_hash(block)
         else:
             return self.substrate.get_chain_head()
diff --git a/bittensor/utils/mock/subtensor_mock.py b/bittensor/utils/mock/subtensor_mock.py
index 9773d525a4..becbd90595 100644
--- a/bittensor/utils/mock/subtensor_mock.py
+++ b/bittensor/utils/mock/subtensor_mock.py
@@ -581,7 +581,7 @@ def query_subtensor(
     ) -> MockSubtensorValue:
         if params is None:
             params = []
-        if block:
+        if block is not None:
             if self.block_number < block:
                 raise Exception("Cannot query block in the future")
 
@@ -622,7 +622,7 @@ def query_map_subtensor(
         """
         if params is None:
             params = []
-        if block:
+        if block is not None:
             if self.block_number < block:
                 raise Exception("Cannot query block in the future")
 
@@ -668,7 +668,7 @@ def query_map_subtensor(
     def query_constant(
         self, module_name: str, constant_name: str, block: Optional[int] = None
     ) -> Optional[object]:
-        if block:
+        if block is not None:
             if self.block_number < block:
                 raise Exception("Cannot query block in the future")
 
@@ -697,7 +697,7 @@ def get_current_block(self) -> int:
     # ==== Balance RPC methods ====
 
     def get_balance(self, address: str, block: int = None) -> "Balance":
-        if block:
+        if block is not None:
             if self.block_number < block:
                 raise Exception("Cannot query block in the future")
 
@@ -732,7 +732,7 @@ def neuron_for_uid(
         if uid is None:
             return NeuronInfo.get_null_neuron()
 
-        if block:
+        if block is not None:
             if self.block_number < block:
                 raise Exception("Cannot query block in the future")
 
@@ -958,7 +958,7 @@ def neuron_for_uid_lite(
         if uid is None:
             return NeuronInfoLite.get_null_neuron()
 
-        if block:
+        if block is not None:
             if self.block_number < block:
                 raise Exception("Cannot query block in the future")