diff --git a/darshan-mpiio-log-format.h b/darshan-mpiio-log-format.h
new file mode 100644
index 0000000000000000000000000000000000000000..5cf0c660d5b4ec2ce5aa47f8ce7ed475711ec52e
--- /dev/null
+++ b/darshan-mpiio-log-format.h
@@ -0,0 +1,26 @@
+/*
+ *  (C) 2015 by Argonne National Laboratory.
+ *      See COPYRIGHT in top-level directory.
+ */
+
+#ifndef __DARSHAN_MPIIO_LOG_FORMAT_H
+#define __DARSHAN_MPIIO_LOG_FORMAT_H
+
+#include "darshan-log-format.h"
+
+enum darshan_mpiio_indices
+{
+    DARSHAN_MPIIO_INDEP_OPENS,   /* independent opens */
+    DARSHAN_MPIIO_COLL_OPENS,    /* collective opens */
+
+    DARSHAN_MPIIO_NUM_INDICES,
+};
+
+struct darshan_mpiio_file
+{
+    darshan_record_id f_id;
+    int64_t rank;
+    int64_t counters[DARSHAN_MPIIO_NUM_INDICES];
+};
+
+#endif /* __DARSHAN_MPIIO_LOG_FORMAT_H */