diff --git a/java/handle.c b/java/handle.c
index fb6870728..c381610d3 100644
--- a/java/handle.c
+++ b/java/handle.c
@@ -96,7 +96,7 @@ Java_com_redhat_et_libguestfs_GuestFS__1close
 
   guestfs_close (g);
 
-  if (len > 0) {
+  if (data && len > 0) {
     size_t i;
     for (i = 0; i < len; ++i) {
       (*env)->DeleteGlobalRef (env, data[i]->callback);
diff --git a/python/handle.c b/python/handle.c
index 9edf98864..3a62d3050 100644
--- a/python/handle.c
+++ b/python/handle.c
@@ -88,7 +88,7 @@ guestfs_int_py_close (PyObject *self, PyObject *args)
   guestfs_close (g);
   Py_END_ALLOW_THREADS;
 
-  if (len > 0) {
+  if (callbacks && len > 0) {
     size_t i;
     for (i = 0; i < len; ++i)
       Py_XDECREF (callbacks[i]);