diff --git a/src/parameters_parser.cc b/src/parameters_parser.cc
index 8ea0fc81..1633aa6b 100644
--- a/src/parameters_parser.cc
+++ b/src/parameters_parser.cc
@@ -7,7 +7,9 @@ String generate_switches_doc(const SwitchMap& switches)
 {
     String res;
     for (auto& sw : switches)
-        res += " -" + sw.key + (sw.value.takes_arg ? " <arg>: " : ": ") + sw.value.description + "\n";
+        res += format(" -{} {}: {}\n", sw.key,
+                      sw.value.takes_arg ? "<arg>" : "",
+                      sw.value.description);
     return res;
 }