diff --git a/pdf.c b/pdf.c
index de83c95928aea9a2cbbb82650e5cbc6b5fed1f3c..dec14d8977aebe130acd46c2fe03cf964aa8cdad 100644
--- a/pdf.c
+++ b/pdf.c
@@ -273,7 +273,8 @@ act_a85group(const HParseResult *p, void *u)
 	b += H_CAST_UINT(digits[4]);
 
 	assert(b <= A85GRPMAX);
-	// TODO: make it generic with H_ACT_APPLY
+	// XXX make it generic with H_ACT_APPLY
+	// XXX but partial groups are at least 2 characters long
 
 	return H_MAKE_UINT(b);
 }