diff --git a/src/plugins/sqldrivers/odbc/qsql_odbc.cpp b/src/plugins/sqldrivers/odbc/qsql_odbc.cpp
index daf9686b5e..1fbbcd0ef1 100644
--- a/src/plugins/sqldrivers/odbc/qsql_odbc.cpp
+++ b/src/plugins/sqldrivers/odbc/qsql_odbc.cpp
@@ -1307,7 +1307,7 @@ QVariant QODBCResult::data(int field)
 bool QODBCResult::isNull(int field)
 {
     Q_D(const QODBCResult);
-    if (field < 0 || field > d->fieldCache.size())
+    if (field < 0 || field >= d->fieldCache.size())
         return true;
     if (field <= d->fieldCacheIdx) {
         // since there is no good way to find out whether the value is NULL