diff --git a/packages/dai-plugin-mcd/contracts/abiMap.js b/packages/dai-plugin-mcd/contracts/abiMap.js
index 55ab01c39..005ff3b43 100644
--- a/packages/dai-plugin-mcd/contracts/abiMap.js
+++ b/packages/dai-plugin-mcd/contracts/abiMap.js
@@ -1,3 +1,4 @@
+// not run through babel, so we must use an ES5-safe export
 module.exports = {
   REP: require('./abis/REP.json'),
   ZRX: require('./abis/ZRX.json'),
diff --git a/packages/dai-plugin-migrations/contracts/abiMap.js b/packages/dai-plugin-migrations/contracts/abiMap.js
index 593d3bd4e..4916d8ebb 100644
--- a/packages/dai-plugin-migrations/contracts/abiMap.js
+++ b/packages/dai-plugin-migrations/contracts/abiMap.js
@@ -1,3 +1,4 @@
+// not run through babel, so we must use an ES5-safe export
 module.exports = {
   TUB: require('./abis/SaiTub'),
   MCD_END_1: require('./abis/End'),
diff --git a/packages/dai-plugin-scd/contracts/abiMap.js b/packages/dai-plugin-scd/contracts/abiMap.js
index c11f338f5..6352b9e47 100644
--- a/packages/dai-plugin-scd/contracts/abiMap.js
+++ b/packages/dai-plugin-scd/contracts/abiMap.js
@@ -1,3 +1,4 @@
+// might not be run through babel in the future, so we must use an ES5-safe export
 module.exports = {
   SAI_PIP: require('./abis/DSValue'),
   SAI_PEP: require('./abis/DSValue'),