diff --git a/packages/babel-generator/src/node/parentheses.js b/packages/babel-generator/src/node/parentheses.js
index b160225288..7fe20066a2 100644
--- a/packages/babel-generator/src/node/parentheses.js
+++ b/packages/babel-generator/src/node/parentheses.js
@@ -199,7 +199,7 @@ export function AssignmentExpression(node: Object): boolean {
   }
 }
 
-// Walk up the print stack to deterimine if our node can come first
+// Walk up the print stack to determine if our node can come first
 // in statement.
 function isFirstInStatement(
   printStack: Array<Object>,
diff --git a/packages/babel-generator/src/printer.js b/packages/babel-generator/src/printer.js
index 59c183a867..0be50e0f29 100644
--- a/packages/babel-generator/src/printer.js
+++ b/packages/babel-generator/src/printer.js
@@ -246,8 +246,10 @@ export default class Printer {
     if (i === str.length) return;
 
     const cha = str[i];
-    if (cha === "\n" || cha === "/") {
-      // we're going to break this terminator expression so we need to add a parentheses
+    const chaPost = str[i + 1];
+
+    // Check for newline or comment
+    if (cha === "\n" || (cha === "/" && (chaPost === "/" || chaPost === "*"))) {
       this.token("(");
       this.indent();
       parenPushNewlineState.printed = true;
diff --git a/packages/babel-generator/test/fixtures/types/ReturnStatement/actual.js b/packages/babel-generator/test/fixtures/types/ReturnStatement/actual.js
index 338c84b966..cadd080008 100644
--- a/packages/babel-generator/test/fixtures/types/ReturnStatement/actual.js
+++ b/packages/babel-generator/test/fixtures/types/ReturnStatement/actual.js
@@ -9,3 +9,7 @@ function bar() {
 function foo() {
   return 1, "foo";
 }
+
+() => { return /a/; }
+
+function foo() { return /a/; }
diff --git a/packages/babel-generator/test/fixtures/types/ReturnStatement/expected.js b/packages/babel-generator/test/fixtures/types/ReturnStatement/expected.js
index 00dbf4a891..7b72e8880c 100644
--- a/packages/babel-generator/test/fixtures/types/ReturnStatement/expected.js
+++ b/packages/babel-generator/test/fixtures/types/ReturnStatement/expected.js
@@ -8,4 +8,12 @@ function bar() {
 
 function foo() {
   return 1, "foo";
-}
\ No newline at end of file
+}
+
+() => {
+  return /a/;
+};
+
+function foo() {
+  return /a/;
+}
diff --git a/packages/babel-generator/test/fixtures/types/ThrowStatement/actual.js b/packages/babel-generator/test/fixtures/types/ThrowStatement/actual.js
index 15dd4fc7b2..e399520fa3 100644
--- a/packages/babel-generator/test/fixtures/types/ThrowStatement/actual.js
+++ b/packages/babel-generator/test/fixtures/types/ThrowStatement/actual.js
@@ -1,3 +1,4 @@
 throw err;
 throw Error("foobar");
 throw new Error("foobar");
+throw /a/;
diff --git a/packages/babel-generator/test/fixtures/types/ThrowStatement/expected.js b/packages/babel-generator/test/fixtures/types/ThrowStatement/expected.js
index 02a2e9dde7..e399520fa3 100644
--- a/packages/babel-generator/test/fixtures/types/ThrowStatement/expected.js
+++ b/packages/babel-generator/test/fixtures/types/ThrowStatement/expected.js
@@ -1,3 +1,4 @@
 throw err;
 throw Error("foobar");
-throw new Error("foobar");
\ No newline at end of file
+throw new Error("foobar");
+throw /a/;