diff --git a/lib/rules/callback-return.js b/lib/rules/callback-return.js
index fa66e6383b7c..4d7bf2aa10e9 100644
--- a/lib/rules/callback-return.js
+++ b/lib/rules/callback-return.js
@@ -52,7 +52,7 @@ module.exports = {
             if (!node.parent) {
                 return null;
             }
-            if (types.indexOf(node.parent.type) === -1) {
+            if (!types.includes(node.parent.type)) {
                 return findClosestParentOfType(node.parent, types);
             }
             return node.parent;
@@ -86,7 +86,7 @@ module.exports = {
          * @returns {boolean} Whether or not this function matches our callback name.
          */
         function isCallback(node) {
-            return containsOnlyIdentifiers(node.callee) && callbacks.indexOf(sourceCode.getText(node.callee)) > -1;
+            return containsOnlyIdentifiers(node.callee) && callbacks.includes(sourceCode.getText(node.callee));
         }
 
         /**
diff --git a/lib/rules/comma-spacing.js b/lib/rules/comma-spacing.js
index 73c10a7711b9..2bf41a00bb66 100644
--- a/lib/rules/comma-spacing.js
+++ b/lib/rules/comma-spacing.js
@@ -181,7 +181,7 @@ module.exports = {
 
                     validateCommaItemSpacing({
                         comma: token,
-                        left: astUtils.isCommaToken(previousToken) || commaTokensToIgnore.indexOf(token) > -1 ? null : previousToken,
+                        left: astUtils.isCommaToken(previousToken) || commaTokensToIgnore.includes(token) ? null : previousToken,
                         right: astUtils.isCommaToken(nextToken) ? null : nextToken
                     }, token);
                 });