diff --git a/src/defs.h b/src/defs.h
index e4a4c49f..290a854d 100644
--- a/src/defs.h
+++ b/src/defs.h
@@ -368,5 +368,15 @@
 
 #define FIXME "FIXME: " __FILE__ ", " STRINGIFY(__LINE__)
 
+#ifndef STATIC_ASSERT
+#   if __STDC_VERSION__ >= 201112L
+#       define STATIC_ASSERT(expr, msg) _Static_assert(expr, msg)
+#   elif defined(static_assert)
+#       define STATIC_ASSERT(expr, msg) static_assert(expr, msg)
+#   else
+#       define STATIC_ASSERT(expr, msg) switch (0) {case 0:case (expr):;}
+#   endif
+#endif /* STATIC_ASSERT */
+
 /* *INDENT-ON* */
 /* clang-format on */