diff --git a/src/validators/crypto_addresses/btc_address.py b/src/validators/crypto_addresses/btc_address.py
index ff401114..a23a071d 100644
--- a/src/validators/crypto_addresses/btc_address.py
+++ b/src/validators/crypto_addresses/btc_address.py
@@ -50,7 +50,7 @@ def btc_address(value: str, /):
 
     return (
         # segwit pattern
-        re.compile(r"^(bc|tc)[0-3][02-9ac-hj-np-z]{14,74}$").match(value)
+        re.compile(r"^(bc|tb)[0-3][02-9ac-hj-np-z]{14,74}$").match(value)
         if value[:2] in ("bc", "tb")
         else _validate_old_btc_address(value)
     )
diff --git a/src/validators/crypto_addresses/eth_address.py b/src/validators/crypto_addresses/eth_address.py
index 84861861..6e9561c5 100644
--- a/src/validators/crypto_addresses/eth_address.py
+++ b/src/validators/crypto_addresses/eth_address.py
@@ -17,11 +17,12 @@
 def _validate_eth_checksum_address(addr: str):
     """Validate ETH type checksum address."""
     addr = addr.replace("0x", "")
-    addr_hash = keccak.new(addr.lower().encode("ascii")).digest().hex()  # type: ignore
 
-    if len(addr) != 40:
+    if not re.fullmatch(r"[0-9a-fA-F]{40}", addr):
         return False
 
+    addr_hash = keccak.new(addr.lower().encode("ascii")).digest().hex()  # type: ignore
+
     for i in range(0, 40):
         if (int(addr_hash[i], 16) > 7 and addr[i].upper() != addr[i]) or (
             int(addr_hash[i], 16) <= 7 and addr[i].lower() != addr[i]
diff --git a/tests/crypto_addresses/test_btc_address.py b/tests/crypto_addresses/test_btc_address.py
index f9c4482e..96647eab 100644
--- a/tests/crypto_addresses/test_btc_address.py
+++ b/tests/crypto_addresses/test_btc_address.py
@@ -17,6 +17,9 @@
         # Bech32/segwit type
         "bc1qar0srrr7xfkvy5l643lydnw9re59gtzzwf5mdq",
         "bc1qc7slrfxkknqcq2jevvvkdgvrt8080852dfjewde450xdlk4ugp7szw5tk9",
+        # Bech32/segwit testnet (tb prefix)
+        "tb1qw508d6qejxtdg4y5r3zarvary0c5xw7kxpjzsx",
+        "tb1qrp33g0q5c5txsp9arysrx4k6zdkfs4nce4xj0gdcccefvpysxf3qccfmv3",
     ],
 )
 def test_returns_true_on_valid_btc_address(value: str):
diff --git a/tests/crypto_addresses/test_eth_address.py b/tests/crypto_addresses/test_eth_address.py
index 2baaad5c..de2fd313 100644
--- a/tests/crypto_addresses/test_eth_address.py
+++ b/tests/crypto_addresses/test_eth_address.py
@@ -37,6 +37,8 @@ def test_returns_true_on_valid_eth_address(value: str):
         "0x7c8EE9977c6f96b6b9774b3e8e4Cc9B93B12b2c",
         "0x7Fb21a171205f3B8d8E4d88A2d2f8A56E45DdB5c",
         "validators.eth",
+        # non-hex characters (the checksum path used to accept these)
+        "0x" + "*" * 40,
     ],
 )
 def test_returns_failed_validation_on_invalid_eth_address(value: str):