diff --git a/format.hpp b/format.hpp
index 6cc98afb..dd3247f7 100644
--- a/format.hpp
+++ b/format.hpp
@@ -265,9 +265,13 @@ namespace cruft::format {
                 break;
 
             case type_t::STRING:
-                if (!std::is_same_v<ValueT, view<const char*>> && !std::is_same_v<ValueT, std::string>)
-                    throw std::runtime_error ("expected string value");
-                break;
+                if (std::is_same_v<ValueT, view<const char*>>)
+                    break;
+                if (std::is_same_v<ValueT, std::string>)
+                    break;
+                if (std::is_same_v<ValueT, std::string_view>)
+                    break;
+                throw std::runtime_error ("expected string value");
 
             case type_t::POINTER:
                 if (!std::is_pointer_v<ValueT> && !std::is_integral_v<ValueT>)