diff --git a/boa/environment.py b/boa/environment.py
index d99d0339..4ea6399a 100644
--- a/boa/environment.py
+++ b/boa/environment.py
@@ -25,6 +25,7 @@
 from boa.util.eip1167 import extract_eip1167_address, is_eip1167_contract
 from boa.util.lrudict import lrudict
 from boa.vm.fork import AccountDBFork
+from boa.vm.fast_accountdb import FastAccountDB
 from boa.vm.gas_meters import GasMeter, NoGasMeter, ProfilingGasMeter
 from boa.vm.utils import to_bytes, to_int
 
@@ -421,6 +422,8 @@ def _init_vm(self, reset_traces=True):
         )
 
         self.vm.state.computation_class = c
+        # TODO: enable this with fast mode
+        # self.vm.state.account_db_class = FastAccountDB
 
         # we usually want to reset the trace data structures
         # but sometimes don't, give caller the option.
diff --git a/boa/vm/fast_accountdb.py b/boa/vm/fast_accountdb.py
new file mode 100644
index 00000000..f948c542
--- /dev/null
+++ b/boa/vm/fast_accountdb.py
@@ -0,0 +1,6 @@
+from eth.db.account import AccountDB
+
+class FastAccountDB(AccountDB):
+    # this is a hotspot in super().
+    def touch_account(self, address):
+        self._accessed_accounts.add(address)