diff --git a/newsfragments/1660.bugfix.rst b/newsfragments/1660.bugfix.rst
new file mode 100644
index 0000000000..a4c1ecd73e
--- /dev/null
+++ b/newsfragments/1660.bugfix.rst
@@ -0,0 +1 @@
+Added formatter rules for eth_tester middleware to allow :meth:`~web3.eth.Eth.getBalance` by using integer block numbers
diff --git a/web3/_utils/module_testing/eth_module.py b/web3/_utils/module_testing/eth_module.py
index c4930d0f73..16bcf3cdfd 100644
--- a/web3/_utils/module_testing/eth_module.py
+++ b/web3/_utils/module_testing/eth_module.py
@@ -126,6 +126,15 @@ def test_eth_getBalance(self, web3: "Web3") -> None:
         assert is_integer(balance)
         assert balance >= 0
 
+    def test_eth_getBalance_with_block_identifier(self, web3: "Web3") -> None:
+        miner_address = web3.eth.getBlock(1)['miner']
+        genesis_balance = web3.eth.getBalance(miner_address, 0)
+        later_balance = web3.eth.getBalance(miner_address, 1)
+
+        assert is_integer(genesis_balance)
+        assert is_integer(later_balance)
+        assert later_balance > genesis_balance
+
     def test_eth_getStorageAt(
         self, web3: "Web3", emitter_contract_address: ChecksumAddress
     ) -> None:
diff --git a/web3/providers/eth_tester/middleware.py b/web3/providers/eth_tester/middleware.py
index b03828abb4..ef07242c79 100644
--- a/web3/providers/eth_tester/middleware.py
+++ b/web3/providers/eth_tester/middleware.py
@@ -225,6 +225,10 @@ def is_hexstr(value: Any) -> bool:
             identity,
             apply_formatter_if(is_not_named_block, to_integer_if_hex),
         ),
+        RPCEndpoint('eth_getBalance'): apply_formatters_to_args(
+            identity,
+            apply_formatter_if(is_not_named_block, to_integer_if_hex),
+        ),
         # EVM
         RPCEndpoint('evm_revert'): apply_formatters_to_args(hex_to_integer),
         # Personal
diff --git a/web3/types.py b/web3/types.py
index 28d3c4ae14..0c8c94dd84 100644
--- a/web3/types.py
+++ b/web3/types.py
@@ -44,7 +44,7 @@
 TValue = TypeVar("TValue")
 
 BlockParams = Literal["latest", "earliest", "pending"]
-BlockIdentifier = Union[BlockParams, BlockNumber, Hash32, HexStr, HexBytes]
+BlockIdentifier = Union[BlockParams, BlockNumber, Hash32, HexStr, HexBytes, int]
 LatestBlockParam = Literal["latest"]
 
 FunctionIdentifier = Union[str, Type[FallbackFn], Type[ReceiveFn]]