diff --git a/client.c b/client.c
index b5f0b54..c0e9022 100644
--- a/client.c
+++ b/client.c
@@ -61,7 +61,7 @@ static ARR_Instance server_addresses;
 
 static int sock_fd = -1;
 
-static int quit = 0;
+static volatile int quit = 0;
 
 static int on_terminal = 0;
 
diff --git a/sched.c b/sched.c
index a4487c3..1f5ebe4 100644
--- a/sched.c
+++ b/sched.c
@@ -111,7 +111,8 @@ static struct timespec last_class_dispatch[SCH_NumberOfClasses];
 
 /* ================================================== */
 
-static int need_to_exit;
+/* Flag terminating the main loop, which can be set from a signal handler */
+static volatile int need_to_exit;
 
 /* ================================================== */