diff --git a/lib/util/mime_utils.js b/lib/util/mime_utils.js
index 6caea138d8..295d4199dc 100644
--- a/lib/util/mime_utils.js
+++ b/lib/util/mime_utils.js
@@ -104,8 +104,8 @@ shaka.util.MimeUtils = class {
    * @return {string}
    */
   static getNormalizedCodec(codecString) {
-    const cb = shaka.util.MimeUtils.getCodecBase(codecString);
-    switch (cb) {
+    const codecBase = shaka.util.MimeUtils.getCodecBase(codecString);
+    switch (codecBase) {
       case 'avc1':
       case 'avc3':
         return 'avc';  // H264
@@ -116,7 +116,7 @@ shaka.util.MimeUtils = class {
       case 'dvhe':
         return 'dovi'; // Dolby Vision
     }
-    return cb;
+    return codecBase;
   }
 
   /**