diff --git a/tests/libqtest.c b/tests/libqtest.c
index 659a3c7c63d6b1a47a0f3c2c1923ef0521108d86..a525dc532c48c9ab2a63e68ed8ec89f030784167 100644
--- a/tests/libqtest.c
+++ b/tests/libqtest.c
@@ -488,6 +488,7 @@ void qtest_qmp_eventwait(QTestState *s, const char *event)
 const char *qtest_get_arch(void)
 {
     const char *qemu = getenv("QTEST_QEMU_BINARY");
+    g_assert(qemu != NULL);
     const char *end = strrchr(qemu, '/');
 
     return end + strlen("/qemu-system-");