diff --git a/src/libsodium/randombytes/internal/randombytes_internal_random.c b/src/libsodium/randombytes/internal/randombytes_internal_random.c
index 1446d1f3..5cee984f 100644
--- a/src/libsodium/randombytes/internal/randombytes_internal_random.c
+++ b/src/libsodium/randombytes/internal/randombytes_internal_random.c
@@ -98,7 +98,11 @@ BOOLEAN NTAPI RtlGenRandom(PVOID RandomBuffer, ULONG RandomBufferLength);
 
 #ifndef TLS
 # ifdef _WIN32
-#  define TLS __declspec(thread)
+#  if (defined __STDC_VERSION__ && __STDC_VERSION__ >= 201112L)
+#   define TLS _Thread_local
+#  else
+#   define TLS __declspec(thread)
+#  endif
 # else
 #  define TLS
 # endif