diff --git a/test/unit/munit.c b/test/unit/munit.c
index 00ede07..be4433a 100644
--- a/test/unit/munit.c
+++ b/test/unit/munit.c
@@ -799,7 +799,11 @@ munit_clock_get_elapsed(struct PsnipClockTimespec* start, struct PsnipClockTimes
 #elif defined(HAVE_STDATOMIC)
 #  include <stdatomic.h>
 #  define ATOMIC_UINT32_T _Atomic uint32_t
-#  define ATOMIC_UINT32_INIT(x) ATOMIC_VAR_INIT(x)
+#  ifdef ATOMIC_VAR_INIT
+#    define ATOMIC_UINT32_INIT(x) ATOMIC_VAR_INIT(x)
+#  else
+#    define ATOMIC_UINT32_INIT(x) (x)
+#  endif
 #elif defined(HAVE_CLANG_ATOMICS)
 #  define ATOMIC_UINT32_T _Atomic uint32_t
 #  define ATOMIC_UINT32_INIT(x) (x)