diff --git a/tests/extendrtests/src/rust/Cargo.toml b/tests/extendrtests/src/rust/Cargo.toml
index b0b422f9ae..6307db3cc0 100644
--- a/tests/extendrtests/src/rust/Cargo.toml
+++ b/tests/extendrtests/src/rust/Cargo.toml
@@ -22,3 +22,4 @@ libR-sys = "*"
 [patch.crates-io]
 # root is `tests/extendrtests/src/rust`
 extendr-api = { path = "../../../../extendr-api/" }
+libR-sys = { path = "../../../../libR-sys/" }
diff --git a/xtask/src/extendrtests/with_absolute_path.rs b/xtask/src/extendrtests/with_absolute_path.rs
index 141ae0b046..e6ae4b83df 100644
--- a/xtask/src/extendrtests/with_absolute_path.rs
+++ b/xtask/src/extendrtests/with_absolute_path.rs
@@ -41,10 +41,20 @@ pub(crate) fn swap_extendr_api_path(shell: &Shell) -> Result<DocumentHandle, Box
 
     let mut replacement = InlineTable::new();
 
-    let item = Value::from(get_replacement_path(&current_path));
+    let item = Value::from(get_replacement_path_extendr_api(&current_path));
     replacement.entry("path").or_insert(item);
     *extendr_api_entry = Value::InlineTable(replacement);
 
+    #[allow(non_snake_case)]
+    let libR_sys_entry =
+        get_libR_sys_entry(&mut cargo_toml).ok_or("`libR-sys` not found in Cargo.toml")?;
+
+    let mut replacement = InlineTable::new();
+
+    let item = Value::from(get_replacement_path_libR_sys(&current_path));
+    replacement.entry("path").or_insert(item);
+    *libR_sys_entry = Value::InlineTable(replacement);
+
     shell.write_file(CARGO_TOML, cargo_toml.to_string())?;
     Ok(DocumentHandle {
         document: original_cargo_toml_bytes,
@@ -52,12 +62,19 @@ pub(crate) fn swap_extendr_api_path(shell: &Shell) -> Result<DocumentHandle, Box
     })
 }
 
-fn get_replacement_path(path: &Path) -> String {
+fn get_replacement_path_extendr_api(path: &Path) -> String {
     let path = path.adjust_for_r();
 
     format!("{path}/extendr-api")
 }
 
+#[allow(non_snake_case)]
+fn get_replacement_path_libR_sys(path: &Path) -> String {
+    let path = path.adjust_for_r();
+
+    format!("{path}/libR-sys")
+}
+
 fn get_extendr_api_entry(document: &mut Document) -> Option<&mut Value> {
     document
         .get_mut("patch")?
@@ -66,6 +83,15 @@ fn get_extendr_api_entry(document: &mut Document) -> Option<&mut Value> {
         .as_value_mut()
 }
 
+#[allow(non_snake_case)]
+fn get_libR_sys_entry(document: &mut Document) -> Option<&mut Value> {
+    document
+        .get_mut("patch")?
+        .get_mut("crates-io")?
+        .get_mut("libR-sys")?
+        .as_value_mut()
+}
+
 fn read_file_with_line_ending<P: AsRef<Path>>(
     shell: &Shell,
     path: P,