diff --git a/lib/sinon/util/core/deep-equal.js b/lib/sinon/util/core/deep-equal.js
index d1d2b6270..b87df09d7 100644
--- a/lib/sinon/util/core/deep-equal.js
+++ b/lib/sinon/util/core/deep-equal.js
@@ -9,6 +9,7 @@ var join = arrayProto.join;
 var sort = arrayProto.sort;
 
 function isReallyNaN(val) {
+    // eslint-disable-next-line no-self-compare
     return val !== val;
 }