diff --git a/techlibs/ice40/ice40_dsp.pmg b/techlibs/ice40/ice40_dsp.pmg
index 9099dd3c4..285e3ceee 100644
--- a/techlibs/ice40/ice40_dsp.pmg
+++ b/techlibs/ice40/ice40_dsp.pmg
@@ -46,17 +46,19 @@ code sigA sigB sigH
 
 	// Only care about those bits that are used
 	int i;
-	for (i = 0; i < GetSize(O); i++) {
-		if (nusers(O[i]) <= 1)
-			break;
-		sigH.append(O[i]);
-	}
+	for (i = GetSize(O) - 1; i > 0 && nusers(O[i]) <= 1; i--)
+		;
 	// This sigM could have no users if downstream sinks (e.g. $add) is
 	//   narrower than $mul result, for example
 	if (i == 0)
 		reject;
 
-	log_assert(nusers(O.extract_end(i)) <= 1);
+	for (int j = 0; j <= i; j++) 
+		if (nusers(O[j]) == 0)
+			sigH.append(module->addWire(NEW_ID));
+		else
+			sigH.append(O[j]);
+
 endcode
 
 code argQ ffA sigA clock clock_pol