1 files changed, 5 insertions, 0 deletions
diff --git a/configure.ac b/configure.ac
index 653f3bb651..67ce5f99d2 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1495,6 +1495,11 @@ done
 AS_IF([test "$rb_cv_func_exported" != no], [
     AC_DEFINE_UNQUOTED(RUBY_FUNC_EXPORTED, [$rb_cv_func_exported extern])
 ])
+RUBY_DECL_ATTRIBUTE([__nonnull__(n)], [RUBY_FUNC_NONNULL(n,x)], [rb_cv_func_nonnull],
+                    [], [function], [
+@%:@define x int conftest_attribute_check(void *p)
+@%:@define n 1
+])
 
 RUBY_APPEND_OPTION(XCFLAGS, -DRUBY_EXPORT)