diff --git a/src/ox/std/string.hpp b/src/ox/std/string.hpp
index 3357f1946..699a39a16 100644
--- a/src/ox/std/string.hpp
+++ b/src/ox/std/string.hpp
@@ -126,6 +126,8 @@ class BasicString {
 
 		constexpr BasicString &operator+=(uint64_t i) noexcept;
 
+		constexpr BasicString &operator+=(std::size_t i) noexcept;
+
 		constexpr BasicString &operator+=(const BasicString &src) noexcept;
 
 		constexpr BasicString operator+(const char *str) const noexcept;
@@ -361,6 +363,13 @@ constexpr BasicString<SmallStringSize> &BasicString<SmallStringSize>::operator+=
 	return this->operator+=(str);
 }
 
+template<std::size_t SmallStringSize>
+constexpr BasicString<SmallStringSize> &BasicString<SmallStringSize>::operator+=(std::size_t i) noexcept {
+	char str[65] = {};
+	ox_itoa(i, str);
+	return this->operator+=(str);
+}
+
 template<std::size_t SmallStringSize>
 constexpr BasicString<SmallStringSize> &BasicString<SmallStringSize>::operator+=(const BasicString &src) noexcept {
 	oxIgnoreError(append(src.c_str(), src.len()));