diff --git a/darshan-runtime/lib/darshan-mpiio.c b/darshan-runtime/lib/darshan-mpiio.c
index 1454fa78467bc84f12057dae9a7d06e1979b27ec..6b3e7a7282f33a4dace1aa94ef7dc198c132e3b1 100644
--- a/darshan-runtime/lib/darshan-mpiio.c
+++ b/darshan-runtime/lib/darshan-mpiio.c
@@ -193,7 +193,7 @@ static int my_rank = -1;
         rec_ref->file_rec->counters[MPIIO_RW_SWITCHES] += 1; \
     rec_ref->last_io_type = DARSHAN_IO_WRITE; \
     if(rec_ref->file_rec->fcounters[MPIIO_F_WRITE_START_TIMESTAMP] == 0 || \
-     rec_ref->file_rec->fcounters[MPIIO_F_READ_START_TIMESTAMP] > __tm1) \
+     rec_ref->file_rec->fcounters[MPIIO_F_WRITE_START_TIMESTAMP] > __tm1) \
         rec_ref->file_rec->fcounters[MPIIO_F_WRITE_START_TIMESTAMP] = __tm1; \
     rec_ref->file_rec->fcounters[MPIIO_F_WRITE_END_TIMESTAMP] = __tm2; \
     if(rec_ref->file_rec->fcounters[MPIIO_F_MAX_WRITE_TIME] < __elapsed) { \