diff --git tests/fileSystem.test tests/fileSystem.test
index 1e6045b250..ee8e694595 100644
--- tests/fileSystem.test
+++ tests/fileSystem.test
@@ -70,7 +70,8 @@ apply {{} {
 		    lappend drives $vol
 		}
 	    }
-	    testConstraint moreThanOneDrive [llength $drives]
+	    testConstraint moreThanOneDrive \
+		    [::tcl::mathop::> [llength $drives] 1]
 	} finally {
 	    cd $dir
 	}
