diff --git a/src/iperf_api.c b/src/iperf_api.c
index 6d6ee84..563aa76 100644
--- a/src/iperf_api.c
+++ b/src/iperf_api.c
@@ -4657,6 +4657,10 @@ diskfile_send(struct iperf_stream *sp)
                 }
                 r = read(sp->diskfile_fd, sp->buffer, sp->test->settings->blksize -
                     sp->diskfile_left);
+                if (r <= 0) {
+                    iperf_err(sp->test, "read failed again %d errno %d\n", r, errno);
+                    return -1;
+                }
             }
             if (r < 0) {
                 iperf_err(sp->test, "read failed with %d\n", errno);