diff --git a/make-pages/SinglePage.hs b/make-pages/SinglePage.hs
index 3d9eea1..dc8d4d2 100644
--- a/make-pages/SinglePage.hs
+++ b/make-pages/SinglePage.hs
@@ -192,10 +192,10 @@ makeDesc (LongDesc fs) = [b|@0
 
 makeButtonBar :: Strict.Text -> [(Image, Size)] -> Builder
 makeButtonBar title images =
-  case length images of
-    0 -> throw $ NoEligibleImages title
-    1 -> ""
-    _ -> [b|@0
+  case images of
+    []  -> throw $ NoEligibleImages title
+    [_] -> ""
+    _   -> [b|@0
       <nav id=alts aria-label="alternate versions">
         <ul class="buttonbar bb-choice">
           $4.alts