diff --git a/packages/babel-parser/src/plugin-utils.js b/packages/babel-parser/src/plugin-utils.js
index 000507c8d7..d8ed23d86d 100644
--- a/packages/babel-parser/src/plugin-utils.js
+++ b/packages/babel-parser/src/plugin-utils.js
@@ -62,7 +62,7 @@ export function validatePlugins(plugins: PluginList) {
   ) {
     throw new Error(
       "'pipelineOperator' requires 'proposal' option whose value should be one of: " +
-        PIPELINE_PROPOSALS.join(", "),
+        PIPELINE_PROPOSALS.map(p => `'${p}'`).join(", "),
     );
   }
 }
diff --git a/packages/babel-parser/test/fixtures/experimental/pipeline-operator/invalid-proposal/options.json b/packages/babel-parser/test/fixtures/experimental/pipeline-operator/invalid-proposal/options.json
index 1697b4bdb7..109111d73a 100644
--- a/packages/babel-parser/test/fixtures/experimental/pipeline-operator/invalid-proposal/options.json
+++ b/packages/babel-parser/test/fixtures/experimental/pipeline-operator/invalid-proposal/options.json
@@ -2,5 +2,5 @@
   "plugins": [
     ["pipelineOperator", { "proposal": "invalid" }]
   ],
-  "throws": "'pipelineOperator' requires 'proposal' option whose value should be one of: minimal, smart"
+  "throws": "'pipelineOperator' requires 'proposal' option whose value should be one of: 'minimal', 'smart'"
 }