diff --git a/auto_tests/TCP_test.c b/auto_tests/TCP_test.c
index 1f3a7f48..f86518b1 100644
--- a/auto_tests/TCP_test.c
+++ b/auto_tests/TCP_test.c
@@ -58,7 +58,7 @@ START_TEST(test_basic)
     ck_assert_msg(tcp_server_listen_count(tcp_s) == NUM_PORTS,
                   "Failed to bind a TCP relay server to all %d attempted ports.", NUM_PORTS);
 
-    Socket sock;
+    Socket sock = {0};
 
     // Check all opened ports for connectivity.
     for (uint8_t i = 0; i < NUM_PORTS; i++) {