diff --git a/src/svm/fifo_segment.c b/src/svm/fifo_segment.c
index dab97a5..6576305 100644
--- a/src/svm/fifo_segment.c
+++ b/src/svm/fifo_segment.c
@@ -232,6 +232,7 @@
       if (!f)
 	return 0;
       memset (f, 0, sizeof (*f));
+      fsh->n_free_bytes -= sizeof (*f);
     }
   else
     {