diff --git a/langfilter/Spans.hs b/langfilter/Spans.hs
index 618ed0f..2ccade9 100644
--- a/langfilter/Spans.hs
+++ b/langfilter/Spans.hs
@@ -91,6 +91,6 @@ abbrs (Str txt) = go $ endash txt where
     = abbr' l : go r
     | (l, r) <- Text.break isAbbr txt
     = Str l : go r
-  abbr' txt = if Text.length txt == 1 then Str txt else abbr txt
+  abbr' txt = if Text.any (not . isDigit) txt then abbr txt else Str txt
   isAbbr c = isUpper c || isDigit c || c `elem` (",.;\\[]" :: String)
 abbrs i = [i]