--- a/gpr/src/gpr-env.adb	2017-11-13 22:16:53.349083426 +0100
+++ b/gpr/src/gpr-env.adb	2017-11-13 22:17:22.692590351 +0100
@@ -1948,6 +1948,8 @@
 
       end if;
 
+      Add_Directories (Self, "/usr/share/gpr");
+
       if Gpr_Prj_Path.all /= "" then
          Add_Directories (Self, Gpr_Prj_Path.all);
       end if;