diff --git a/packages/babel-core/src/config/config-chain.js b/packages/babel-core/src/config/config-chain.js
index f46d0ee2acf0..b9e13a130797 100644
--- a/packages/babel-core/src/config/config-chain.js
+++ b/packages/babel-core/src/config/config-chain.js
@@ -542,7 +542,7 @@ function normalizeOptions(opts: ValidatedOptions): ValidatedOptions {
 
   // "sourceMap" is just aliased to sourceMap, so copy it over as
   // we merge the options together.
-  if (options.sourceMap) {
+  if (options.hasOwnProperty("sourceMap")) {
     options.sourceMaps = options.sourceMap;
     delete options.sourceMap;
   }
diff --git a/packages/babel-plugin-transform-runtime/src/index.js b/packages/babel-plugin-transform-runtime/src/index.js
index 88fe373cc022..7fb69f49d5ea 100644
--- a/packages/babel-plugin-transform-runtime/src/index.js
+++ b/packages/babel-plugin-transform-runtime/src/index.js
@@ -72,6 +72,9 @@ export default declare((api, options, dirname) => {
         `but got ${JSON.stringify(corejsVersion)}.`,
     );
   }
+  if (typeof runtimeVersion !== "string") {
+    throw new Error(`The 'version' option must be a version string.`);
+  }
 
   function has(obj, key) {
     return Object.prototype.hasOwnProperty.call(obj, key);