diff --git a/gnatcoll_shared.gpr.in b/gnatcoll_shared.gpr.in
index f189c9db..64ff0741 100644
--- a/gnatcoll_shared.gpr.in
+++ b/gnatcoll_shared.gpr.in
@@ -76,12 +76,12 @@ abstract project GnatColl_Shared is
             for Switches ("Ada") use
               ("-g", "-O0", "-gnata", "-gnatVa", "-gnatQ", "-gnaty", "-gnateE",
                "-gnatwaCJe");
-            for Switches ("C") use ("-g", "-Wunreachable-code");
+            for Switches ("C") use ("-g", "-Wunreachable-code", "-fPIC");
 
          when "Production" =>
             --  Do not use -gnatwe for production mode
             for Switches ("Ada") use ("-O2", "-gnatn", "-gnatwaCJ");
-            for Switches ("C") use ("-O2", "-Wunreachable-code");
+            for Switches ("C") use ("-O2", "-Wunreachable-code", "-fPIC");
       end case;
 
       case Syslog is