diff --git a/code/__HELPERS/type2type.dm b/code/__HELPERS/type2type.dm
index b962907d043..dcf304314bb 100644
--- a/code/__HELPERS/type2type.dm
+++ b/code/__HELPERS/type2type.dm
@@ -43,9 +43,9 @@
 	return num
 
 //Returns the hex value of a number given a value assumed to be a base-ten value
-/proc/num2hex(num, placeholder)
-	if(!isnum(num)) return
-	if(placeholder == null) placeholder = 2
+/proc/num2hex(num, placeholder = 2)
+	if(!isnum(num) || num < 0)
+		return
 
 	var/hex = ""
 	while(num)