diff --git a/packages/calypso-build/CHANGELOG.md b/packages/calypso-build/CHANGELOG.md
index 0e50ca2c4187b..9dab739b74cae 100644
--- a/packages/calypso-build/CHANGELOG.md
+++ b/packages/calypso-build/CHANGELOG.md
@@ -1,3 +1,8 @@
+# [Unreleased]
+
+- Added transform-runtime versioning to babel/default.js
+  This will need to be kept up to date while https://github.com/babel/babel/issues/10261 is unresolved.
+
 # 3.0.0
 
 - Switch to `@wordpress/dependency-extraction-webpack-plugin` from
diff --git a/packages/calypso-build/babel/default.js b/packages/calypso-build/babel/default.js
index a8daff26c7695..021904d6579af 100644
--- a/packages/calypso-build/babel/default.js
+++ b/packages/calypso-build/babel/default.js
@@ -22,6 +22,9 @@ module.exports = () => ( {
 				helpers: true,
 				regenerator: false,
 				useESModules: false,
+				// Needed so that helpers aren't duplicated.
+				// This will need to be kept up to date while https://github.com/babel/babel/issues/10261 is unresolved.
+				version: '7.5.5',
 			},
 		],
 	],