diff --git a/pango/opentype/hb-ot-layout-gsubgpos-private.hh b/pango/opentype/hb-ot-layout-gsubgpos-private.hh
index b21939a..20d180a 100644
--- a/pango/opentype/hb-ot-layout-gsubgpos-private.hh
+++ b/pango/opentype/hb-ot-layout-gsubgpos-private.hh
@@ -567,7 +567,7 @@ struct ChainRule
     const ArrayOf<LookupRecord> &lookup = CONST_NEXT (ArrayOf<LookupRecord>, lookahead);
     return chain_context_lookup (APPLY_ARG,
 				 backtrack.len, backtrack.array,
-				 input.len, input.array + 1,
+				 input.len, input.array,
 				 lookahead.len, lookahead.array,
 				 lookup.len, lookup.array,
 				 lookup_context);
