diff --git a/code/modules/mob/living/simple_animal/bot/medbot.dm b/code/modules/mob/living/simple_animal/bot/medbot.dm
index 70c6c30d946..c1ca349c041 100644
--- a/code/modules/mob/living/simple_animal/bot/medbot.dm
+++ b/code/modules/mob/living/simple_animal/bot/medbot.dm
@@ -497,6 +497,8 @@
 
 /mob/living/simple_animal/bot/medbot/proc/check_overdose(mob/living/carbon/patient,reagent_id,injection_amount)
 	var/datum/reagent/R  = chemical_reagents_list[reagent_id]
+	if(!R.overdose_threshold) //Some chems do not have an OD threshold
+		return 0
 	var/current_volume = patient.reagents.get_reagent_amount(reagent_id)
 	if(current_volume + injection_amount > R.overdose_threshold)
 		return 1