--- acinclude.m4.org	2006-10-25 17:52:48.000000000 +0200
+++ acinclude.m4	2006-10-25 17:53:15.000000000 +0200
@@ -16,7 +16,7 @@
       PILOT_CFLAGS="-I$with_pilot_link/include"
       PILOT_LIBS="-L$with_pilot_link/lib -Wl,-R$with_pilot_link/lib -lpisock"
     else
-      PILOT_CFLAGS=""
+      PILOT_CFLAGS="-I/usr/include/libpisock"
       PILOT_LIBS="-lpisock"
     fi