diff --git a/codespan-reporting/src/diagnostic.rs b/codespan-reporting/src/diagnostic.rs
index 8f017ba..828aff1 100644
--- a/codespan-reporting/src/diagnostic.rs
+++ b/codespan-reporting/src/diagnostic.rs
@@ -113,7 +113,7 @@ impl<FileId> Label<FileId> {
 /// Represents a diagnostic message that can provide information like errors and
 /// warnings to the user.
 ///
-/// The position of a Diagnostic is considered to be the position of the [`Label`] with a style of [`LabelStyle::primary`] that has the smallest start position.
+/// The position of a Diagnostic is considered to be the position of the [`Label`] that has the earliest starting position and has the highest style which appears in all the labels of the diagnostic.
 #[derive(Clone, Debug)]
 #[cfg_attr(feature = "serialization", derive(Serialize, Deserialize))]
 pub struct Diagnostic<FileId> {
diff --git a/codespan-reporting/src/term/views.rs b/codespan-reporting/src/term/views.rs
index 59cdcc5..076a237 100644
--- a/codespan-reporting/src/term/views.rs
+++ b/codespan-reporting/src/term/views.rs
@@ -119,10 +119,11 @@ where
             {
                 Some(labeled_file) => {
                     // another diagnostic also referenced this file
-                    if labeled_file.start > label.range.start
-                        && labeled_file.max_label_style >= label.style
+                    if labeled_file.max_label_style > label.style
+                        || (labeled_file.max_label_style == label.style
+                            && labeled_file.start > label.range.start)
                     {
-                        // this label indicates an earlier start and has at least the same level of style
+                        // this label has a higher style or has the same style but starts earlier
                         labeled_file.start = label.range.start;
                         labeled_file.location = files
                             .location(label.file_id, label.range.start)
diff --git a/codespan-reporting/tests/term.rs b/codespan-reporting/tests/term.rs
index 4a0fa26..8b1bf2d 100644
--- a/codespan-reporting/tests/term.rs
+++ b/codespan-reporting/tests/term.rs
@@ -569,9 +569,10 @@ mod multiline_overlapping {
                     .with_message("match arms have incompatible types")
                     .with_code("E0308")
                     .with_labels(vec![
+                        // this secondary label is before the primary label to test the locus calculation (see issue #259)
+                        Label::secondary((), 89..134).with_message("this is found to be of type `Result<ByteIndex, LineIndexOutOfBoundsError>`"),
                         Label::primary((), 230..351).with_message("expected enum `Result`, found struct `LineIndexOutOfBoundsError`"),
                         Label::secondary((), 8..362).with_message("`match` arms have incompatible types"),
-                        Label::secondary((), 89..134).with_message("this is found to be of type `Result<ByteIndex, LineIndexOutOfBoundsError>`"),
                         Label::secondary((), 167..195).with_message("this is found to be of type `Result<ByteIndex, LineIndexOutOfBoundsError>`"),
                     ])
                     .with_notes(vec![unindent::unindent(