diff --git a/include/site/linux-uclibc b/include/site/linux-uclibc
index 458030bcd2d..3b6c422b47e 100644
--- a/include/site/linux-uclibc
+++ b/include/site/linux-uclibc
@@ -64,5 +64,5 @@ ac_cv_uint=yes
 ac_cv_uint64_t=yes
 ac_cv_ulong=yes
 ac_cv_ushort=yes
-ac_cv_va_copy=no
+ac_cv_va_copy=C99
 ac_cv_va_val_copy=yes