diff --git a/testsuite/ada/gnat_compare/gnat_compare.adb b/testsuite/ada/gnat_compare/gnat_compare.adb
index 934f51477..9c05b2309 100644
--- a/testsuite/ada/gnat_compare/gnat_compare.adb
+++ b/testsuite/ada/gnat_compare/gnat_compare.adb
@@ -284,6 +284,7 @@ procedure GNAT_Compare is
          Put_Line ("Could not locate gprbuild on the PATH");
       end if;
 
+      Args.Append (+"-c");
       Args.Append (+"-q");
       Args.Append (+"-p");
       Args.Append (+"-P" & Project_File);