diff --git a/src/main/java/ru/dmitriymx/corrector1s/Corrector1S.java b/src/main/java/ru/dmitriymx/corrector1s/Corrector1S.java
index b2c54bb..dc27283 100644
--- a/src/main/java/ru/dmitriymx/corrector1s/Corrector1S.java
+++ b/src/main/java/ru/dmitriymx/corrector1s/Corrector1S.java
@@ -65,7 +65,7 @@ public class Corrector1S {
 
     private String buildSumFormula(int column, int startLine, int endLine) {
         String columnChar = CellReference.convertNumToColString(column);
-        return String.format("SUM(%s%d:%s%d)", columnChar, startLine, columnChar, endLine);
+        return String.format("SUM(%s%d:%s%d)", columnChar, startLine+1, columnChar, endLine+1);
     }
 
     public void check() throws Exception {