diff --git a/src/machine/machine_table.c b/src/machine/machine_table.c
index 24ef3d4e9..a22599b71 100644
--- a/src/machine/machine_table.c
+++ b/src/machine/machine_table.c
@@ -220,5 +220,6 @@ machine_get_machine_from_internal_name(char *s)
 void
 machine_close(void)
 {
-    machines[machine].nvr_close();
+    if (machines[machine].nvr_close)
+    	machines[machine].nvr_close();
 }
diff --git a/src/nvr_at.c b/src/nvr_at.c
index 3ba4547df..4db6b1595 100644
--- a/src/nvr_at.c
+++ b/src/nvr_at.c
@@ -76,6 +76,9 @@ nvr_read(uint16_t addr, void *priv)
 void
 nvr_at_close(void)
 {
+    if (nvrp == NULL)
+	return;
+
     if (nvrp->fname != NULL)
 	free(nvrp->fname);