diff --git a/src/crypto/internal.h b/src/crypto/internal.h
index 2e94399c2..63e6a662f 100644
--- a/src/crypto/internal.h
+++ b/src/crypto/internal.h
@@ -126,7 +126,9 @@
 #endif
 
 #if !defined(__cplusplus)
-#if defined(_MSC_VER) && !defined(__clang__)
+#if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201112L
+#include <stdalign.h>
+#elif defined(_MSC_VER) && !defined(__clang__)
 #define alignas(x) __declspec(align(x))
 #define alignof __alignof
 #else
@@ -135,11 +137,13 @@
 // compilers have long implemented C11 and made it default. The most likely
 // cause of pre-C11 modes is stale -std=c99 or -std=gnu99 flags in build
 // configuration. Such flags can be removed.
-#if __STDC_VERSION__ < 201112L
+//
+// TODO(davidben): In MSVC 2019 16.8 or higher (_MSC_VER >= 1928),
+// |__STDC_VERSION__| will be 201112 when passed /std:c11 and unset otherwise.
+// C11 alignas and alignof are only implemented in C11 mode. Can we mandate C11
+// mode for those versions?
 #error "BoringSSL must be built in C11 mode or higher."
 #endif
-#include <stdalign.h>
-#endif
 #endif
 
 #if defined(OPENSSL_THREADS) && \