diff --git a/src/uncategorized/salon.tw b/src/uncategorized/salon.tw
index 2b5fb58a56339ea098e863be6c5af4add0698830..6809d0945f2bf9750b55071087c13a93d33cf4fe 100644
--- a/src/uncategorized/salon.tw
+++ b/src/uncategorized/salon.tw
@@ -434,10 +434,10 @@ Set horn color:
 		| Custom length: <<textbox "_newHLength" _oldHLength "Salon">>
 		<<if $showInches >= 1>>
 			cm (<<= cmToInchString($activeSlave.hLength)>>)
-			[[Apply|Salon][cashX(forceNeg($modCost), "slaveMod", $activeSlave), $activeSlave.hLength = Number(_newHLength)]]
+			[[Apply|Salon][cashX(forceNeg($modCost), "slaveMod", $activeSlave), $activeSlave.hLength = (Number(_newHLength) || $activeSlave.hLength)]]
 		<<else>>
 			cm
-			[[Apply|Salon][cashX(forceNeg($modCost), "slaveMod", $activeSlave), $activeSlave.hLength = Number(_newHLength)]]
+			[[Apply|Salon][cashX(forceNeg($modCost), "slaveMod", $activeSlave), $activeSlave.hLength = (Number(_newHLength) || $activeSlave.hLength)]]
 		<</if>>