diff --git a/libraries/DataFlash/DataFlash_File.cpp b/libraries/DataFlash/DataFlash_File.cpp
index fde93e0d9f..b0d19b6528 100644
--- a/libraries/DataFlash/DataFlash_File.cpp
+++ b/libraries/DataFlash/DataFlash_File.cpp
@@ -652,8 +652,8 @@ void DataFlash_File::_io_timer(void)
     uint32_t tnow = hal.scheduler->micros();
     if (nbytes < _writebuf_chunk && 
         tnow - _last_write_time < 2000000UL) {
-        // write in 512 byte chunks, but always write at least once
-        // per 2 seconds if data is available
+        // write in _writebuf_chunk-sized chunks, but always write at
+        // least once per 2 seconds if data is available
         return;
     }