diff --git a/docs/api.rst b/docs/api.rst
index d96185db36..355484c2f4 100644
--- a/docs/api.rst
+++ b/docs/api.rst
@@ -62,7 +62,7 @@ Returns an object with the following properties:
 * ``language``: detected language
 * ``relevance``: integer value representing the relevance score
 * ``value``: HTML string with highlighting markup
-* ``second_best``: object with the same structure for second-best heuristically detected language (may be absent)
+* ``secondBest``: object with the same structure for second-best heuristically detected language (may be absent)
 
 
 fixMarkup
diff --git a/src/highlight.js b/src/highlight.js
index 4260fb09b9..911d569408 100644
--- a/src/highlight.js
+++ b/src/highlight.js
@@ -619,7 +619,7 @@ const HLJS = function(hljs) {
   - language (detected language)
   - relevance (int)
   - value (an HTML string with highlighting markup)
-  - second_best (object with the same structure for second-best heuristically
+  - secondBest (object with the same structure for second-best heuristically
     detected language, may be absent)
 
     @param {string} code
@@ -660,7 +660,7 @@ const HLJS = function(hljs) {
 
     /** @type {AutoHighlightResult} */
     const result = best;
-    result.second_best = secondBest;
+    result.secondBest = secondBest;
 
     return result;
   }
@@ -761,12 +761,12 @@ const HLJS = function(hljs) {
       re: result.relevance,
       relavance: result.relevance
     };
-    if (result.second_best) {
-      element.second_best = {
-        language: result.second_best.language,
+    if (result.secondBest) {
+      element.secondBest = {
+        language: result.secondBest.language,
         // TODO: remove with version 11.0
-        re: result.second_best.relevance,
-        relavance: result.second_best.relevance
+        re: result.secondBest.relevance,
+        relavance: result.secondBest.relevance
       };
     }
   }
diff --git a/tools/checkAutoDetect.js b/tools/checkAutoDetect.js
index 4836a557b0..f4ff21ed0e 100755
--- a/tools/checkAutoDetect.js
+++ b/tools/checkAutoDetect.js
@@ -26,13 +26,13 @@ function testAutoDetection(language, index, languages) {
     .forEach(function(content) {
       const expected = language,
             actual   = hljs.highlightAuto(content);
-      if (actual.language !== expected && actual.second_best.language !== expected) {
+      if (actual.language !== expected && actual.secondBest.language !== expected) {
         return resultTable.push([
           expected,
           colors.red(actual.language),
           actual.relevance ? actual.relevance : colors.grey('None'),
-          colors.red(actual.second_best.language),
-          actual.second_best.relevance ? actual.second_best.relevance : colors.grey('None')
+          colors.red(actual.secondBest.language),
+          actual.secondBest.relevance ? actual.secondBest.relevance : colors.grey('None')
         ]);
       }
       if (actual.language !== expected) {
@@ -40,18 +40,18 @@ function testAutoDetection(language, index, languages) {
           expected,
           colors.yellow(actual.language),
           actual.relevance ? actual.relevance : colors.grey('None'),
-          colors.yellow(actual.second_best.language),
-          actual.second_best.relevance ? actual.second_best.relevance : colors.grey('None')
+          colors.yellow(actual.secondBest.language),
+          actual.secondBest.relevance ? actual.secondBest.relevance : colors.grey('None')
         ]);
       }
       // equal relevance is flagged
-      if (actual.relevance == actual.second_best.relevance) {
+      if (actual.relevance == actual.secondBest.relevance) {
         return resultTable.push([
           expected,
           actual.language,
           actual.relevance ? colors.yellow(actual.relevance) : colors.grey('None'),
-          actual.second_best.language,
-          actual.second_best.relevance ? colors.yellow(actual.second_best.relevance) : colors.grey('None'),
+          actual.secondBest.language,
+          actual.secondBest.relevance ? colors.yellow(actual.secondBest.relevance) : colors.grey('None'),
           "Relevance match."
         ]);
       }
diff --git a/tools/developer.html b/tools/developer.html
index b446aacd13..f01722d392 100644
--- a/tools/developer.html
+++ b/tools/developer.html
@@ -215,8 +215,8 @@ <h3>Markup</h3>
         vue.language = hljs.getLanguage(language) ? language : '';
 
         var rendering_stats = result.language + ': relevance ' + (result.relevance );
-        if (result.second_best) {
-            rendering_stats += ', ' + result.second_best.language + ': ' + (result.second_best.relevance || result.second_best.r);
+        if (result.secondBest) {
+            rendering_stats += ', ' + result.secondBest.language + ': ' + (result.secondBest.relevance || result.secondBest.r);
         }
         editor.find('.rendering_stats').text(rendering_stats);
         editor.find('.rendering_time').text(rendering_time);
diff --git a/types/index.d.ts b/types/index.d.ts
index c912c5a756..45f7ca5b5d 100644
--- a/types/index.d.ts
+++ b/types/index.d.ts
@@ -82,7 +82,7 @@ interface HighlightResult {
     sofar? : string
     errorRaised? : Error
     // * for auto-highlight
-    second_best? : Omit<HighlightResult, 'second_best'>
+    secondBest? : Omit<HighlightResult, 'secondBest'>
     code?: string
 }
 interface AutoHighlightResult extends HighlightResult {}
@@ -143,7 +143,7 @@ interface CallbackResponse {
 type AnnotatedError = Error & {mode?: Mode | Language, languageName?: string, badRule?: Mode}
 
 type ModeCallback = (match: RegExpMatchArray, response: CallbackResponse) => void
-type HighlightedHTMLElement = HTMLElement & {result?: object, second_best?: object, parentNode: HTMLElement}
+type HighlightedHTMLElement = HTMLElement & {result?: object, secondBest?: object, parentNode: HTMLElement}
 type EnhancedMatch = RegExpMatchArray & {rule: CompiledMode, type: MatchType}
 type MatchType = "begin" | "end" | "illegal"