diff --git a/docs/rules/no-unused-expressions.md b/docs/rules/no-unused-expressions.md
index 480915ee223..8a9748d3d06 100644
--- a/docs/rules/no-unused-expressions.md
+++ b/docs/rules/no-unused-expressions.md
@@ -2,7 +2,7 @@
 
 An unused expression which has no effect on the state of the program indicates a logic error.
 
-For example, `n + 1;` is not a syntax error, but it might be a typing mistake where a programmer meant an assignment statement `n += 1;` instead.
+For example, `n + 1;` is not a syntax error, but it might be a typing mistake where a programmer meant an assignment statement `n += 1;` instead. Sometimes, such unused expressions may be eliminated by some build tools in production environment, which possibly breaks application logic.
 
 ## Rule Details