diff --git a/tools/src/h5perf/sio_engine.c b/tools/src/h5perf/sio_engine.c
index 700416d7198..2363f6a0d99 100644
--- a/tools/src/h5perf/sio_engine.c
+++ b/tools/src/h5perf/sio_engine.c
@@ -139,9 +139,7 @@ do_sio(parameters param, results *res)
     /* IO type */
     iot = param.io_type;
 
-    if (NULL == (fname = calloc(FILENAME_MAX, sizeof(char))))
-        GOTOERROR(FAIL);
-
+    /* MUST initialize fd early since we check its file IDs in cleanup code */
     switch (iot) {
         case POSIXIO:
             fd.posixfd  = -1;
@@ -157,6 +155,9 @@ do_sio(parameters param, results *res)
             GOTOERROR(FAIL);
     }
 
+    if (NULL == (fname = calloc(FILENAME_MAX, sizeof(char))))
+        GOTOERROR(FAIL);
+
     linear_buf_size = 1;
 
     for (i = 0; i < param.rank; i++) {