diff --git a/lib/rules/multiline-comment-style.js b/lib/rules/multiline-comment-style.js
index 5bea92ded7b..17c297fad7e 100644
--- a/lib/rules/multiline-comment-style.js
+++ b/lib/rules/multiline-comment-style.js
@@ -286,8 +286,7 @@ module.exports = {
                                 fix(fixer) {
                                     const lineStartIndex = sourceCode.getIndexFromLoc({ line: lineNumber, column: 0 });
                                     const [linePrefix, whitespaceBefore, whitespaceAfter] = lineText.match(/^(\s*)\*?(\s*)/u);
-                                    const commentStartIndex = lineStartIndex + linePrefix.length;
-                                    const leadingWhitespace = whitespaceAfter || ` ${
+                                    const leadingWhitespace = whitespaceAfter.length && whitespaceAfter || ` ${
                                         whitespaceBefore.startsWith(expectedLeadingWhitespace)
                                             ? whitespaceBefore.replace(expectedLeadingWhitespace, "")
                                             : ""
@@ -295,6 +294,7 @@ module.exports = {
                                     const replacementText = lineNumber === firstComment.loc.end.line || lineText.length === linePrefix.length
                                         ? expectedLinePrefix
                                         : `${expectedLinePrefix}${leadingWhitespace}`;
+                                    const commentStartIndex = lineStartIndex + linePrefix.length;
 
                                     return fixer.replaceTextRange([lineStartIndex, commentStartIndex], replacementText);
                                 }
diff --git a/tests/lib/rules/multiline-comment-style.js b/tests/lib/rules/multiline-comment-style.js
index b44ea0a05d5..047e4e4f0c7 100644
--- a/tests/lib/rules/multiline-comment-style.js
+++ b/tests/lib/rules/multiline-comment-style.js
@@ -1160,6 +1160,210 @@ ruleTester.run("multiline-comment-style", rule, {
             `,
             options: ["separate-lines"],
             errors: [{ messageId: "expectedLines", line: 2 }]
+        },
+        {
+            code: `
+                /*
+                 * foo
+                 *
+                 * bar
+                 */
+            `,
+            output: `
+                /* foo
+${"                   "}
+                   bar */
+            `,
+            options: ["bare-block"],
+            errors: [{ messageId: "expectedBareBlock", line: 2 }]
+        },
+        {
+            code: `
+                /*
+                 * foo
+                 *${" "}
+                 * bar
+                 */
+            `,
+            output: `
+                /* foo
+${"                   "}
+                   bar */
+            `,
+            options: ["bare-block"],
+            errors: [{ messageId: "expectedBareBlock", line: 2 }]
+        },
+        {
+            code: `
+                // foo
+                //
+                // bar
+            `,
+            output: `
+                /*
+                 * foo
+                 *${" "}
+                 * bar
+                 */
+            `,
+            options: ["starred-block"],
+            errors: [{ messageId: "expectedBlock", line: 2 }]
+        },
+        {
+            code: `
+                // foo
+                //${" "}
+                // bar
+            `,
+            output: `
+                /*
+                 * foo
+                 *${" "}
+                 * bar
+                 */
+            `,
+            options: ["starred-block"],
+            errors: [{ messageId: "expectedBlock", line: 2 }]
+        },
+        {
+            code: `
+                // foo
+                //
+                // bar
+            `,
+            output: `
+                /* foo
+${"                   "}
+                   bar */
+            `,
+            options: ["bare-block"],
+            errors: [{ messageId: "expectedBlock", line: 2 }]
+        },
+        {
+            code: `
+                // foo
+                //${" "}
+                // bar
+            `,
+            output: `
+                /* foo
+${"                   "}
+                   bar */
+            `,
+            options: ["bare-block"],
+            errors: [{ messageId: "expectedBlock", line: 2 }]
+        },
+        {
+            code: `
+                /* foo
+
+                   bar */
+            `,
+            output: `
+                // foo
+                //${" "}
+                // bar${" "}
+            `,
+            options: ["separate-lines"],
+            errors: [{ messageid: "expectedlines", line: 2 }]
+        },
+        {
+            code: `
+                /* foo
+${"                   "}
+                   bar */
+            `,
+            output: `
+                // foo
+                //${" "}
+                // bar${" "}
+            `,
+            options: ["separate-lines"],
+            errors: [{ messageid: "expectedlines", line: 2 }]
+        },
+        {
+            code: `
+                /* foo
+
+                   bar */
+            `,
+            output: `
+                /*
+                 * foo
+                 *
+                 * bar
+                 */
+            `,
+            options: ["starred-block"],
+            errors: [
+                { messageId: "startNewline", line: 2 },
+                { messageId: "missingStar", line: 3 },
+                { messageId: "missingStar", line: 4 },
+                { messageId: "endNewline", line: 4 }
+            ]
+        },
+        {
+            code: `
+                /* foo
+${"                   "}
+                   bar */
+            `,
+            output: `
+                /*
+                 * foo
+                 *
+                 * bar
+                 */
+            `,
+            options: ["starred-block"],
+            errors: [
+                { messageId: "startNewline", line: 2 },
+                { messageId: "missingStar", line: 3 },
+                { messageId: "missingStar", line: 4 },
+                { messageId: "endNewline", line: 4 }
+            ]
+        },
+        {
+            code: `
+                /*foo
+
+                  bar */
+            `,
+            output: `
+                /*
+                 *foo
+                 *
+                 *bar${" "}
+                 */
+            `,
+            options: ["starred-block"],
+            errors: [
+                { messageId: "startNewline", line: 2 },
+                { messageId: "missingStar", line: 3 },
+                { messageId: "missingStar", line: 4 },
+                { messageId: "endNewline", line: 4 }
+            ]
+        },
+        {
+            code: `
+                /*foo
+${"                   "}
+                  bar */
+            `,
+            output: `
+                /*
+                 *foo
+                 *
+                 *bar${" "}
+                 */
+            `,
+            options: ["starred-block"],
+            errors: [
+                { messageId: "startNewline", line: 2 },
+                { messageId: "missingStar", line: 3 },
+                { messageId: "missingStar", line: 4 },
+                { messageId: "endNewline", line: 4 }
+            ]
         }
     ]
 });