diff --git a/tvix/eval/src/builtins/mod.rs b/tvix/eval/src/builtins/mod.rs
index 81d30e91c..dc3ea3fc1 100644
--- a/tvix/eval/src/builtins/mod.rs
+++ b/tvix/eval/src/builtins/mod.rs
@@ -27,6 +27,9 @@ use self::versions::{VersionPart, VersionPartsIter};
 mod to_xml;
 mod versions;
 
+#[cfg(test)]
+pub use to_xml::value_to_xml;
+
 #[cfg(feature = "impure")]
 mod impure;
 
diff --git a/tvix/eval/src/builtins/to_xml.rs b/tvix/eval/src/builtins/to_xml.rs
index 6d486d356..250891b60 100644
--- a/tvix/eval/src/builtins/to_xml.rs
+++ b/tvix/eval/src/builtins/to_xml.rs
@@ -11,7 +11,7 @@ use crate::{ErrorKind, Value};
 
 /// Recursively serialise a value to XML. The value *must* have been
 /// deep-forced before being passed to this function.
-pub(super) fn value_to_xml<W: Write>(mut writer: W, value: &Value) -> Result<(), ErrorKind> {
+pub fn value_to_xml<W: Write>(mut writer: W, value: &Value) -> Result<(), ErrorKind> {
     let config = EmitterConfig {
         perform_indent: true,
         pad_self_closing: true,