diff --git a/lix/libutil/config-impl.hh b/lix/libutil/config-impl.hh
index d25ec5fd1..7c9a5aa1e 100644
--- a/lix/libutil/config-impl.hh
+++ b/lix/libutil/config-impl.hh
@@ -127,6 +127,7 @@ void BaseSetting<T>::convertToArg(Args & args, const std::string & category)
 DECLARE_CONFIG_SERIALISER(std::string)
 DECLARE_CONFIG_SERIALISER(std::optional<std::string>)
 DECLARE_CONFIG_SERIALISER(std::optional<uint16_t>)
+DECLARE_CONFIG_SERIALISER(std::optional<uint32_t>)
 DECLARE_CONFIG_SERIALISER(bool)
 DECLARE_CONFIG_SERIALISER(Strings)
 DECLARE_CONFIG_SERIALISER(StringSet)
diff --git a/lix/libutil/config.cc b/lix/libutil/config.cc
index fe0be4408..3948eee94 100644
--- a/lix/libutil/config.cc
+++ b/lix/libutil/config.cc
@@ -181,11 +181,30 @@ template<> std::optional<uint16_t> BaseSetting<std::optional<uint16_t>>::parse(c
         throw UsageError("setting '%s' has invalid value '%s'", name, str);
 }
 
+template<>
+std::optional<uint32_t>
+BaseSetting<std::optional<uint32_t>>::parse(const std::string & str, const ApplyConfigOptions & options) const
+{
+    if (str == "") {
+        return std::nullopt;
+    } else if (auto n = string2Int<uint32_t>(str)) {
+        return n;
+    } else {
+        throw UsageError("setting '%s' has invalid value '%s'", name, str);
+    }
+}
+
 template<> std::string BaseSetting<std::optional<uint16_t>>::to_string() const
 {
     return value ? std::to_string(*value) : "";
 }
 
+template<>
+std::string BaseSetting<std::optional<uint32_t>>::to_string() const
+{
+    return value ? std::to_string(*value) : "";
+}
+
 template<> bool BaseSetting<bool>::parse(const std::string & str, const ApplyConfigOptions & options) const
 {
     if (str == "true" || str == "yes" || str == "1")