diff --git a/build.rs b/build.rs
index 7d9ee83e..2843c758 100644
--- a/build.rs
+++ b/build.rs
@@ -22,6 +22,7 @@ fn main() {
       "node.c",
       "parser.c",
       "stack.c",
+      "string_input.c",
       "subtree.c",
       "tree_cursor.c",
       "tree.c",