diff --git a/tests/test_etcp_router_unit.c b/tests/test_etcp_router_unit.c
index 8b1ee3d4..b3d49779 100644
--- a/tests/test_etcp_router_unit.c
+++ b/tests/test_etcp_router_unit.c
@@ -111,7 +111,7 @@ static int test_total = 0, test_passed = 0, test_failed = 0;
 } while(0)
 
 #define PASS() do { puts("PASS"); test_passed++; } while(0)
-#define FAIL(msg) do { printf("FAIL: %s\n", msg); test_failed++; return; } while(0)
+#define FAIL(msg) do { printf("FAIL: %s\n", msg); test_failed++; return -1; } while(0)
 
 // ======================== Tests ========================