diff --git a/trixy-parser/src/error.rs b/trixy-parser/src/error.rs
index b865754..e75cb0b 100644
--- a/trixy-parser/src/error.rs
+++ b/trixy-parser/src/error.rs
@@ -74,13 +74,19 @@ impl ErrorContext {
             .expect("This should work, as have *at least* one (index = 0) line"))
         .to_owned();
 
+        // Make the span relative to the current line
         let contexted_span = {
-            let matched_line: Vec<_> = original_file.match_indices(&line).collect();
+            // `spanned_line` should be a subset of `line`
+            let spanned_line = &original_file[span.start..span.end];
+
+            let matched_line: Vec<_> = line.match_indices(&spanned_line).collect();
+            assert!(!matched_line.is_empty());
             let (index, matched_line) = matched_line.first().expect("This first index should always match, as we took the line from the string in the first place");
-            debug_assert_eq!(matched_line, &&line);
+            debug_assert_eq!(matched_line, &spanned_line);
+
             TokenSpan {
-                start: span.start - index,
-                end: span.end - index,
+                start: *index,
+                end: (span.end - span.start) + index,
             }
         };
 
@@ -94,7 +100,7 @@ impl ErrorContext {
             .to_owned()
         };
 
-        let line_below = if lines.len() - 1 > line_number {
+        let line_below = if lines.len() > line_number {
             // We have a line after the current line
             (*lines
                 .get((line_number + 1) - 1)