diff --git a/README.md b/README.md
index 070c998d0..c8883460f 100644
--- a/README.md
+++ b/README.md
@@ -10996,6 +10996,16 @@ module.exports = class GraphQL {
 };
 // Options: [{"checkRestProperty":true}]
 // Message: Missing JSDoc @param "fetchOptions.url" declaration.
+
+(function() {
+	/**
+	 * A function.
+	 */
+	function f(param) {
+		return !param;
+	}
+})();
+// Message: Missing JSDoc @param "param" declaration.
 ````
 
 The following patterns are not considered problems:
diff --git a/src/jsdocUtils.js b/src/jsdocUtils.js
index ade6b5ae5..dfd8e7d50 100644
--- a/src/jsdocUtils.js
+++ b/src/jsdocUtils.js
@@ -767,7 +767,7 @@ const getTagsByType = (context, mode, tags, tagPreference) => {
 
 const getIndent = (sourceCode) => {
   let indent = sourceCode.text.match(/^\n*([ \t]+)/u);
-  indent = indent ? indent[1] + indent[1].charAt() : ' ';
+  indent = indent ? indent[1] + ' ' : ' ';
 
   return indent;
 };
diff --git a/test/rules/assertions/requireParam.js b/test/rules/assertions/requireParam.js
index f02fea009..83103a6a4 100644
--- a/test/rules/assertions/requireParam.js
+++ b/test/rules/assertions/requireParam.js
@@ -1928,6 +1928,36 @@ export default {
       `,
       parser: require.resolve('babel-eslint'),
     },
+    /* eslint-disable no-tabs */
+    {
+      code: `
+(function() {
+	/**
+	 * A function.
+	 */
+	function f(param) {
+		return !param;
+	}
+})();
+      `,
+      errors: [
+        {
+          message: 'Missing JSDoc @param "param" declaration.',
+        },
+      ],
+      output: `
+(function() {
+	/**
+	 * A function.
+	 * @param param
+	 */
+	function f(param) {
+		return !param;
+	}
+})();
+      `,
+      /* eslint-enable no-tabs */
+    },
   ],
   valid: [
     {