diff --git a/acinclude.m4 b/acinclude.m4
index ba025e3..c6b2b26 100644
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -564,7 +564,8 @@ else
     echo "s/@%:@def[]ine  *\\(@<:@m4_cr_LETTERS[]_@:>@@<:@_symbol@:>@*\\)\\(.*\\)/@%:@ifndef $_UPP""_\\1 \\" >> _script
     echo "@%:@def[]ine $_UPP""_\\1 \\2 \\" >> _script
     echo "@%:@endif/" >>_script
-    echo "s/@%:@def[]ine  *\\(@<:@m4_cr_letters@:>@@<:@_symbol@:>@*\\)\\(.*\\)/@%:@ifndef $_LOW""_\\1 \\" >> _script
+    # no! these are things like socklen_t, const, vfork
+    # echo "s/@%:@def[]ine  *\\(@<:@m4_cr_letters@:>@@<:@_symbol@:>@*\\)\\(.*\\)/@%:@ifndef $_LOW""_\\1 \\" >> _script
     echo "@%:@define $_LOW""_\\1 \\2 \\" >> _script
     echo "@%:@endif/" >> _script
     # now executing _script on _DEF input to create _OUT output file