diff --git a/dbms/src/IO/ReadBufferAIO.cpp b/dbms/src/IO/ReadBufferAIO.cpp
index 162a83b7b94..f47e04bff75 100644
--- a/dbms/src/IO/ReadBufferAIO.cpp
+++ b/dbms/src/IO/ReadBufferAIO.cpp
@@ -254,7 +254,7 @@ void ReadBufferAIO::prepare()
     /// Region of the disk from which we want to read data.
     const off_t region_begin = first_unread_pos_in_file;
 
-    if ((static_cast<off_t>(requested_byte_count) > std::numeric_limits<off_t>::max()) ||
+    if ((requested_byte_count > std::numeric_limits<off_t>::max()) ||
         (first_unread_pos_in_file > (std::numeric_limits<off_t>::max() - static_cast<off_t>(requested_byte_count))))
         throw Exception("An overflow occurred during file operation", ErrorCodes::LOGICAL_ERROR);
 
diff --git a/dbms/src/IO/WriteBufferAIO.cpp b/dbms/src/IO/WriteBufferAIO.cpp
index 37661473d9c..2fe7da27809 100644
--- a/dbms/src/IO/WriteBufferAIO.cpp
+++ b/dbms/src/IO/WriteBufferAIO.cpp
@@ -274,7 +274,7 @@ void WriteBufferAIO::prepare()
     /// Region of the disk in which we want to write data.
     const off_t region_begin = pos_in_file;
 
-    if ((static_cast<off_t>(flush_buffer.offset()) > std::numeric_limits<off_t>::max()) ||
+    if ((flush_buffer.offset() > std::numeric_limits<off_t>::max()) ||
         (pos_in_file > (std::numeric_limits<off_t>::max() - static_cast<off_t>(flush_buffer.offset()))))
         throw Exception("An overflow occurred during file operation", ErrorCodes::LOGICAL_ERROR);