diff --git a/passes/opt/opt_clean.cc b/passes/opt/opt_clean.cc
index 3892c7581..661871d87 100644
--- a/passes/opt/opt_clean.cc
+++ b/passes/opt/opt_clean.cc
@@ -271,6 +271,9 @@ bool compare_signals(RTLIL::SigBit &s1, RTLIL::SigBit &s2, SigPool &regs, SigPoo
 			return conns.check_any(s2);
 	}
 
+	if (w1 == w2)
+		return s2.offset < s1.offset;
+
 	if (w1->port_output != w2->port_output)
 		return w2->port_output;