diff --git a/test/externalTests/brink.sh b/test/externalTests/brink.sh
index 48cc4028f3d7..d8ad001ac014 100755
--- a/test/externalTests/brink.sh
+++ b/test/externalTests/brink.sh
@@ -64,6 +64,7 @@ function brink_test
     # TODO: Remove this when Brink merges https://github.com/brinktrade/brink-core/pull/52
     sed -i "s|\(function isValidSignature(bytes \)calldata\( _data, bytes \)calldata\( _signature)\)|\1memory\2memory\3|g" src/Test/MockEIP1271Validator.sol
 
+    neutralize_package_lock
     neutralize_package_json_hooks
     force_hardhat_compiler_binary "$config_file" "$BINARY_TYPE" "$BINARY_PATH"
     force_hardhat_compiler_settings "$config_file" "$(first_word "$SELECTED_PRESETS")" "$config_var" "$CURRENT_EVM_VERSION" "$extra_settings" "$extra_optimizer_settings"
diff --git a/test/externalTests/elementfi.sh b/test/externalTests/elementfi.sh
index f3ecbb14170f..f34a169e9512 100755
--- a/test/externalTests/elementfi.sh
+++ b/test/externalTests/elementfi.sh
@@ -99,9 +99,7 @@ function elementfi_test
     # "ProviderError: Too Many Requests error received from eth-mainnet.alchemyapi.io"
     rm test/mockERC20YearnVaultTest.ts
 
-    # Several tests fail unless we use the exact versions hard-coded in package-lock.json
-    #neutralize_package_lock
-
+    neutralize_package_lock
     neutralize_package_json_hooks
     force_hardhat_compiler_binary "$config_file" "$BINARY_TYPE" "$BINARY_PATH"
     force_hardhat_compiler_settings "$config_file" "$(first_word "$SELECTED_PRESETS")" "$config_var"
diff --git a/test/externalTests/gnosis.sh b/test/externalTests/gnosis.sh
index 218a5a7504b5..416d36153623 100755
--- a/test/externalTests/gnosis.sh
+++ b/test/externalTests/gnosis.sh
@@ -76,6 +76,7 @@ function gnosis_safe_test
     sed -i "s|\(it\)\((\"can be used only via DELEGATECALL opcode\"\)|\1.skip\2|g" test/libraries/SignMessageLib.spec.ts
     sed -i "s|it\((\"can only be called from Safe itself\"\)|it.skip\1|g" test/libraries/Migration.spec.ts
 
+    neutralize_package_lock
     neutralize_package_json_hooks
     force_hardhat_compiler_binary "$config_file" "$BINARY_TYPE" "$BINARY_PATH"
     force_hardhat_compiler_settings "$config_file" "$(first_word "$SELECTED_PRESETS")" "$config_var"
diff --git a/test/externalTests/pool-together.sh b/test/externalTests/pool-together.sh
index f841206ef2a9..0fc8aafbd69d 100755
--- a/test/externalTests/pool-together.sh
+++ b/test/externalTests/pool-together.sh
@@ -66,6 +66,9 @@ function pool_together_test
     force_hardhat_compiler_binary "$config_file" "$BINARY_TYPE" "$BINARY_PATH"
     force_hardhat_compiler_settings "$config_file" "$(first_word "$SELECTED_PRESETS")" "$config_var"
     yarn install
+    # Hardhat 2.20.0 is the last version that works. Newer versions throw this error:
+    # Unexpected config HardhatConfig.networks.hardhat.initialBaseFeePerGas found - This field is only valid for networks with EIP-1559. Try a newer hardfork or remove it.
+    yarn add hardhat@2.20.0
 
     # These come with already compiled artifacts. We want them recompiled with latest compiler.
     rm -r node_modules/@pooltogether/yield-source-interface/artifacts/