diff --git a/frontends/aiger/aigerparse.cc b/frontends/aiger/aigerparse.cc
index c3cc6b321..56e4f3b2c 100644
--- a/frontends/aiger/aigerparse.cc
+++ b/frontends/aiger/aigerparse.cc
@@ -135,6 +135,7 @@ static void parse_aiger_ascii(RTLIL::Design *design, std::istream &f, std::strin
 
         module->addDff(NEW_ID, clk_wire, d_wire, q_wire);
 
+        // Reset logic is optional in AIGER 1.9
         if (f.peek() == ' ') {
             if (!(f >> l3))
                 log_error("Line %d cannot be interpreted as a latch!\n", line_count);