diff --git a/test-server/test-client.c b/test-server/test-client.c
index 949d3988..4c2b07a5 100644
--- a/test-server/test-client.c
+++ b/test-server/test-client.c
@@ -38,7 +38,7 @@ static int deny_deflate;
 static int deny_mux;
 static struct libwebsocket *wsi_mirror;
 static int mirror_lifetime = 0;
-static int force_exit = 0;
+static volatile int force_exit = 0;
 static int longlived = 0;
 
 /*
diff --git a/test-server/test-echo.c b/test-server/test-echo.c
index 2402f198..09794398 100644
--- a/test-server/test-echo.c
+++ b/test-server/test-echo.c
@@ -41,7 +41,7 @@
 
 #include "../lib/libwebsockets.h"
 
-int force_exit = 0;
+static volatile int force_exit = 0;
 
 #define MAX_ECHO_PAYLOAD 1400
 #define LOCAL_RESOURCE_PATH INSTALL_DATADIR"/libwebsockets-test-server"
diff --git a/test-server/test-server.c b/test-server/test-server.c
index eb275c58..4573a529 100644
--- a/test-server/test-server.c
+++ b/test-server/test-server.c
@@ -58,7 +58,7 @@ int max_poll_elements;
 struct pollfd *pollfds;
 int *fd_lookup;
 int count_pollfds;
-int force_exit = 0;
+static volatile int force_exit = 0;
 
 /*
  * This demo server shows how to use libwebsockets for one or more