diff --git a/krb5/install_check.pl b/krb5/install_check.pl
index 615f6b212..bf36a50db 100644
--- a/krb5/install_check.pl
+++ b/krb5/install_check.pl
@@ -8,5 +8,5 @@ do 'krb5-lib.pl';
 # For mode 0, returns 1 if installed, 0 if not
 sub is_installed
 {
-return $_[0] ? 2 : 1;
+return !-r $config{'krb5_conf'} ? 0 : $_[0] ? 2 : 1;
 }