diff --git a/code/modules/reagents/chemistry/reagents/other_reagents.dm b/code/modules/reagents/chemistry/reagents/other_reagents.dm
index 8f27f4637fb..d38b1659018 100644
--- a/code/modules/reagents/chemistry/reagents/other_reagents.dm
+++ b/code/modules/reagents/chemistry/reagents/other_reagents.dm
@@ -1007,7 +1007,7 @@
 
 /datum/reagent/mercury/on_mob_life(mob/living/carbon/affected_mob, seconds_per_tick, times_fired)
 	. = ..()
-	if(!HAS_TRAIT(src, TRAIT_IMMOBILIZED) && !isspaceturf(affected_mob.loc))
+	if(!HAS_TRAIT(src, TRAIT_IMMOBILIZED) && isturf(affected_mob.loc) && !isgroundlessturf(affected_mob.loc))
 		step(affected_mob, pick(GLOB.cardinals))
 	if(SPT_PROB(3.5, seconds_per_tick))
 		affected_mob.emote(pick("twitch","drool","moan"))
@@ -1119,7 +1119,7 @@
 
 /datum/reagent/lithium/on_mob_life(mob/living/carbon/affected_mob, seconds_per_tick, times_fired)
 	. = ..()
-	if(!HAS_TRAIT(affected_mob, TRAIT_IMMOBILIZED) && !isspaceturf(affected_mob.loc) && isturf(affected_mob.loc))
+	if(!HAS_TRAIT(affected_mob, TRAIT_IMMOBILIZED) && isturf(affected_mob.loc) && !isgroundlessturf(affected_mob.loc))
 		step(affected_mob, pick(GLOB.cardinals))
 	if(SPT_PROB(2.5, seconds_per_tick))
 		affected_mob.emote(pick("twitch","drool","moan"))