diff --git a/packages/babel-generator/src/printer.js b/packages/babel-generator/src/printer.js
index 1941b94ace..b7b319293c 100644
--- a/packages/babel-generator/src/printer.js
+++ b/packages/babel-generator/src/printer.js
@@ -557,6 +557,9 @@ export default class Printer {
       val = val.replace(/\n(?!$)/g, `\n${repeat(" ", indentSize)}`);
     }
 
+    // Avoid creating //* comments
+    if (this.endsWith("/")) this._space();
+
     this.withSource("start", comment.loc, () => {
       this._append(val);
     });
diff --git a/packages/babel-generator/test/fixtures/comments/slash-before-leading-comment-compact/actual.js b/packages/babel-generator/test/fixtures/comments/slash-before-leading-comment-compact/actual.js
new file mode 100644
index 0000000000..38ca6ef4f4
--- /dev/null
+++ b/packages/babel-generator/test/fixtures/comments/slash-before-leading-comment-compact/actual.js
@@ -0,0 +1 @@
+var foo = 1 / /* leading */ 1;
diff --git a/packages/babel-generator/test/fixtures/comments/slash-before-leading-comment-compact/expected.js b/packages/babel-generator/test/fixtures/comments/slash-before-leading-comment-compact/expected.js
new file mode 100644
index 0000000000..bc8b496231
--- /dev/null
+++ b/packages/babel-generator/test/fixtures/comments/slash-before-leading-comment-compact/expected.js
@@ -0,0 +1 @@
+var foo=1/ /* leading */1;
diff --git a/packages/babel-generator/test/fixtures/comments/slash-before-leading-comment-compact/options.json b/packages/babel-generator/test/fixtures/comments/slash-before-leading-comment-compact/options.json
new file mode 100644
index 0000000000..eb4e948bfa
--- /dev/null
+++ b/packages/babel-generator/test/fixtures/comments/slash-before-leading-comment-compact/options.json
@@ -0,0 +1,3 @@
+{
+  "compact": true
+}