diff --git a/src/ch03.tex b/src/ch03.tex
index 420abe7..e4c3114 100644
--- a/src/ch03.tex
+++ b/src/ch03.tex
@@ -643,7 +643,7 @@ \subsection{数组}
             let mut j = i * i;
             while j < 10000 {
                 sieve[j] = false;
-                j += 1;
+                j += i;
             }
         }
     }