diff --git a/src/keys.cc b/src/keys.cc
index e3b2f111..f21f93ec 100644
--- a/src/keys.cc
+++ b/src/keys.cc
@@ -36,7 +36,7 @@ static const KeyAndName keynamemap[] = {
     { "backtab", Key::BackTab },
 };
 
-KeyList parse_keys(const String& str)
+KeyList parse_keys(StringView str)
 {
     KeyList result;
     for (ByteCount pos = 0; pos < str.length(); ++pos)
@@ -51,7 +51,7 @@ KeyList parse_keys(const String& str)
             {
                 Key::Modifiers modifier = Key::Modifiers::None;
 
-                String keyname = str.substr(pos+1, end_pos - pos - 1);
+                auto keyname = str.substr(pos+1, end_pos - pos - 1);
                 if (keyname.length() > 2)
                 {
                     if (tolower(keyname[0]) == 'c' and keyname[1] == '-')
diff --git a/src/keys.hh b/src/keys.hh
index de775552..d64cee2e 100644
--- a/src/keys.hh
+++ b/src/keys.hh
@@ -66,7 +66,7 @@ struct Key
 
 using KeyList = std::vector<Key>;
 
-KeyList parse_keys(const String& str);
+KeyList parse_keys(StringView str);
 String  key_to_str(Key key);
 
 constexpr Key alt(Codepoint key) { return { Key::Modifiers::Alt, key }; }