diff --git a/data/spot.py b/data/spot.py
index 32f2221..de5a22e 100644
--- a/data/spot.py
+++ b/data/spot.py
@@ -243,7 +243,7 @@ class Spot:
         # should catch e.g. POTA comments like "2-fer: GB-0001 GB-0002".
         if self.comment and self.sig_refs and len(self.sig_refs) > 0:
             sig = self.sig_refs[0].sig.upper()
-            all_comment_ref_matches = re.finditer(r"(^|\W)" + get_ref_regex_for_sig(sig) + r"(^|\W)", self.comment)
+            all_comment_ref_matches = re.finditer(r"(^|\W)" + get_ref_regex_for_sig(sig) + r"(^|\W)", self.comment, re.IGNORECASE)
             for ref_match in all_comment_ref_matches:
                 self.append_sig_ref_if_missing(SIGRef(id=ref_match.group(2).upper(), sig=sig))