diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 12dda6c541d..9e3d6bc27ac 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,8 @@
+2018-08-25  Simon Marchi  <simon.marchi@polymtl.ca>
+
+	* python/py-threadevent.c (py_get_event_thread): Initialize
+	pythread.
+
 2018-08-24  Pedro Alves  <palves@redhat.com>
 
 	* python/py-bpevent.c (create_breakpoint_event_object): Use
diff --git a/gdb/python/py-threadevent.c b/gdb/python/py-threadevent.c
index a78f0a38310..4f822b4ae09 100644
--- a/gdb/python/py-threadevent.c
+++ b/gdb/python/py-threadevent.c
@@ -25,7 +25,7 @@
 PyObject *
 py_get_event_thread (ptid_t ptid)
 {
-  PyObject *pythread;
+  PyObject *pythread = nullptr;
 
   if (non_stop)
     {
@@ -36,7 +36,7 @@ py_get_event_thread (ptid_t ptid)
   else
     pythread = Py_None;
 
-  if (!pythread)
+  if (pythread == nullptr)
     {
       PyErr_SetString (PyExc_RuntimeError, "Could not find event thread");
       return NULL;