diff --git a/setup.cfg b/setup.cfg
index 6a7ef78..3ebe338 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -63,7 +63,7 @@ exclude =
 # `pip install eth-prototype[PDF]` like:
 # PDF = ReportLab; RXP
 web3 =
-    web3
+    web3>=6
 
 defender =
     boto3
@@ -79,7 +79,7 @@ testing =
     pytest-cov
 
 testing-w3 =
-    web3[tester]
+    web3[tester]>=6
     setuptools
     pytest
     pytest-cov
diff --git a/src/ethproto/w3wrappers.py b/src/ethproto/w3wrappers.py
index bebf72c..6b3c127 100644
--- a/src/ethproto/w3wrappers.py
+++ b/src/ethproto/w3wrappers.py
@@ -97,7 +97,7 @@ def transact(provider, function, tx_kwargs):
         else:  # it's a string, I try to get the PK from the environment
             from_ = provider.address_book.get_signer_account(from_)
             tx_kwargs["from"] = from_.address
-        tx = function.buildTransaction(
+        tx = function.build_transaction(
             {
                 **tx_kwargs,
                 **{"nonce": provider.w3.eth.get_transaction_count(from_.address)},
@@ -109,7 +109,7 @@ def transact(provider, function, tx_kwargs):
         from .defender_relay import send_transaction
 
         tx_kwargs = {**provider.tx_kwargs, **tx_kwargs}
-        tx = function.buildTransaction(tx_kwargs)
+        tx = function.build_transaction(tx_kwargs)
         return send_transaction(tx)
 
     return provider.w3.eth.wait_for_transaction_receipt(tx_hash)
diff --git a/src/ethproto/wrappers.py b/src/ethproto/wrappers.py
index 1e8b4a8..68c975f 100644
--- a/src/ethproto/wrappers.py
+++ b/src/ethproto/wrappers.py
@@ -49,10 +49,6 @@ def auto_register_provider(provider_key):
         from .w3wrappers import register_w3_provider
 
         register_w3_provider()
-    elif provider_key == "brownie":
-        from .brwrappers import BrownieProvider
-
-        register_provider("brownie", BrownieProvider())
     else:
         raise RuntimeError(f"Unknown provider {provider_key}")