diff --git a/contracts/RlnBase.sol b/contracts/RlnBase.sol
index bf1db5a..cff9a39 100644
--- a/contracts/RlnBase.sol
+++ b/contracts/RlnBase.sol
@@ -87,7 +87,7 @@ abstract contract RlnBase {
 
     /// Allows a user to register as a member
     /// @param idCommitment The idCommitment of the member
-    function register(uint256 idCommitment) external payable {
+    function register(uint256 idCommitment) external payable virtual {
         if (msg.value != MEMBERSHIP_DEPOSIT) {
             revert InsufficientDeposit(MEMBERSHIP_DEPOSIT, msg.value);
         }
@@ -98,7 +98,7 @@ abstract contract RlnBase {
     /// Registers a member
     /// @param idCommitment The idCommitment of the member
     /// @param stake The amount of eth staked by the member
-    function _register(uint256 idCommitment, uint256 stake) internal {
+    function _register(uint256 idCommitment, uint256 stake) internal virtual {
         if (members[idCommitment] != 0) revert DuplicateIdCommitment();
         if (idCommitmentIndex >= SET_SIZE) revert FullTree();
 
@@ -114,7 +114,7 @@ abstract contract RlnBase {
 
     /// @dev Allows a user to slash a member
     /// @param idCommitment The idCommitment of the member
-    function slash(uint256 idCommitment, address payable receiver, uint256[8] calldata proof) external {
+    function slash(uint256 idCommitment, address payable receiver, uint256[8] calldata proof) external virtual {
         _validateSlash(idCommitment, receiver, proof);
         _slash(idCommitment, receiver, proof);
     }
@@ -123,7 +123,7 @@ abstract contract RlnBase {
     /// stake to the receiver's available withdrawal balance
     /// @param idCommitment The idCommitment of the member
     /// @param receiver The address to receive the funds
-    function _slash(uint256 idCommitment, address payable receiver, uint256[8] calldata proof) internal {
+    function _slash(uint256 idCommitment, address payable receiver, uint256[8] calldata proof) internal virtual {
         if (receiver == address(this) || receiver == address(0)) {
             revert InvalidReceiverAddress(receiver);
         }
@@ -157,7 +157,7 @@ abstract contract RlnBase {
         virtual;
 
     /// Allows a user to withdraw funds allocated to them upon slashing a member
-    function withdraw() external {
+    function withdraw() external virtual {
         uint256 amount = withdrawalBalance[msg.sender];
 
         if (amount == 0) revert InsufficientWithdrawalBalance();
@@ -181,6 +181,7 @@ abstract contract RlnBase {
     function _verifyProof(uint256 idCommitment, address receiver, uint256[8] calldata proof)
         internal
         view
+        virtual
         returns (bool)
     {
         return verifier.verifyProof(
diff --git a/docs/index.md b/docs/index.md
index 26b9c26..b17362c 100644
--- a/docs/index.md
+++ b/docs/index.md
@@ -1068,7 +1068,7 @@ constructor(uint256 membershipDeposit, uint256 depth, address _poseidonHasher, a
 ### register
 
 ```solidity
-function register(uint256 idCommitment) external payable
+function register(uint256 idCommitment) external payable virtual
 ```
 
 Allows a user to register as a member
@@ -1082,7 +1082,7 @@ Allows a user to register as a member
 ### \_register
 
 ```solidity
-function _register(uint256 idCommitment, uint256 stake) internal
+function _register(uint256 idCommitment, uint256 stake) internal virtual
 ```
 
 Registers a member
@@ -1105,7 +1105,7 @@ _Inheriting contracts MUST override this function_
 ### slash
 
 ```solidity
-function slash(uint256 idCommitment, address payable receiver, uint256[8] proof) external
+function slash(uint256 idCommitment, address payable receiver, uint256[8] proof) external virtual
 ```
 
 _Allows a user to slash a member_
@@ -1121,7 +1121,7 @@ _Allows a user to slash a member_
 ### \_slash
 
 ```solidity
-function _slash(uint256 idCommitment, address payable receiver, uint256[8] proof) internal
+function _slash(uint256 idCommitment, address payable receiver, uint256[8] proof) internal virtual
 ```
 
 _Slashes a member by removing them from the set, and adding their
@@ -1144,7 +1144,7 @@ function _validateSlash(uint256 idCommitment, address payable receiver, uint256[
 ### withdraw
 
 ```solidity
-function withdraw() external
+function withdraw() external virtual
 ```
 
 Allows a user to withdraw funds allocated to them upon slashing a member
@@ -1167,7 +1167,7 @@ NOTE: The variant of Poseidon we use accepts only 1 input, assume n=2, and the s
 ### \_verifyProof
 
 ```solidity
-function _verifyProof(uint256 idCommitment, address receiver, uint256[8] proof) internal view returns (bool)
+function _verifyProof(uint256 idCommitment, address receiver, uint256[8] proof) internal view virtual returns (bool)
 ```
 
 _Groth16 proof verification_