diff --git a/output/src/op_transform.rs b/output/src/op_transform.rs
index a18a63a..c9426df 100644
--- a/output/src/op_transform.rs
+++ b/output/src/op_transform.rs
@@ -38,8 +38,13 @@ macro_rules! transform_xy {
                 if let Some(Token { value: Value::Key(k), .. }) = iter.peek() {
                     if k == $x || k == $y || k == $xy {
                         let _ = iter.next().unwrap();
-                        let token = iter.next().expect("no content specified");
-                        let content = state.get_content(&token.value).expect("no content provided");
+                        let token = iter.next()
+                            .expect("no content specified");
+                        let content = if let Some(content) = state.get_content(&token.value) {
+                            content
+                        } else {
+                            panic!("no content corresponding to for {:?}", &token);
+                        };
                         return Some(match k {
                             $x => Self::x(content),
                             $y => Self::y(content),