diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index dc4346ec048..1469366b1fc 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,11 @@
+2018-09-11  Xavier Roirand  <roirand@adacore.com>
+
+	* darwin-nat.h (struct darwin_thread_info) <gdb_port,
+	inf_port, msg_state>: Initialize.
+	(struct darwin_thread_info) <signaled, single_step>: Change
+	type and initialize.
+	(struct darwin_thread_info) <event>: Initialize.
+
 2018-09-10  Sergio Durigan Junior  <sergiodj@redhat.com>
 
 	PR gdb/23555
diff --git a/gdb/darwin-nat.h b/gdb/darwin-nat.h
index 5965df08ab6..89a7c06f6a1 100644
--- a/gdb/darwin-nat.h
+++ b/gdb/darwin-nat.h
@@ -114,25 +114,25 @@ enum darwin_msg_state
 struct darwin_thread_info : public private_thread_info
 {
   /* The thread port from a GDB point of view.  */
-  thread_t gdb_port;
+  thread_t gdb_port = 0;
 
   /* The thread port from the inferior point of view.  Not to be used inside
      gdb except for get_ada_task_ptid.  */
-  thread_t inf_port;
+  thread_t inf_port = 0;
 
   /* Current message state.
      If the kernel has sent a message it expects a reply and the inferior
      can't be killed before.  */
-  enum darwin_msg_state msg_state;
+  enum darwin_msg_state msg_state = DARWIN_RUNNING;
 
   /* True if this thread is single-stepped.  */
-  unsigned char single_step;
+  bool single_step = false;
 
   /* True if a signal was manually sent to the thread.  */
-  unsigned char signaled;
+  bool signaled = false;
 
   /* The last exception received.  */
-  struct darwin_exception_msg event;
+  struct darwin_exception_msg event {};
 };
 typedef struct darwin_thread_info darwin_thread_t;