diff --git a/src/operation_transformation.rs b/src/operation_transformation.rs
index 85e3995..bc01e34 100644
--- a/src/operation_transformation.rs
+++ b/src/operation_transformation.rs
@@ -1,8 +1,10 @@
+mod diff_error;
 mod edited_text;
 mod operation;
 mod utils;
 use std::fmt::Debug;
 
+pub use diff_error::DiffError;
 pub use edited_text::EditedText;
 pub use operation::Operation;
 
diff --git a/src/wasm.rs b/src/wasm.rs
index 1b7a24b..6fc02f2 100644
--- a/src/wasm.rs
+++ b/src/wasm.rs
@@ -105,16 +105,17 @@ pub fn diff(parent: &str, changed: &TextWithCursors, tokenizer: BuiltinTokenizer
 pub fn undiff(parent: &str, diff: Vec<JsValue>, tokenizer: BuiltinTokenizer) -> String {
     set_panic_hook();
 
-    EditedText::from_diff(
+    match EditedText::from_diff(
         parent,
         diff.into_iter()
             .map(std::convert::TryInto::try_into)
             .collect::<Result<_, _>>()
             .expect("Invalid diff format"),
         &*tokenizer,
-    )
-    .apply()
-    .text()
+    ) {
+        Ok(edited_text) => edited_text.apply().text(),
+        Err(e) => panic!("{}", e),
+    }
 }
 
 fn set_panic_hook() {
diff --git a/tests/test.rs b/tests/test.rs
index 2b14b86..2e54e6c 100644
--- a/tests/test.rs
+++ b/tests/test.rs
@@ -57,9 +57,9 @@ fn test_document_one_way_with_serialisation() {
                 .unwrap();
 
         let restored_left_operations =
-            EditedText::from_diff(&parent, serialised_left, &*BuiltinTokenizer::Word);
+            EditedText::from_diff(&parent, serialised_left, &*BuiltinTokenizer::Word).unwrap();
         let restored_right_operations =
-            EditedText::from_diff(&parent, serialised_right, &*BuiltinTokenizer::Word);
+            EditedText::from_diff(&parent, serialised_right, &*BuiltinTokenizer::Word).unwrap();
 
         doc.assert_eq_without_cursors(
             &restored_left_operations