diff --git a/CppCoreGuidelines.md b/CppCoreGuidelines.md
index 58ceefa..f4be493 100644
--- a/CppCoreGuidelines.md
+++ b/CppCoreGuidelines.md
@@ -11137,7 +11137,7 @@ Complicated expressions are error-prone.
     // bad: assignment hidden in subexpression
     while ((c = getc()) != -1)
 
-    // bad: two non-local variables assigned in a sub-expressions
+    // bad: two non-local variables assigned in sub-expressions
     while ((cin >> c1, cin >> c2), c1 == c2)
 
     // better, but possibly still too complicated