diff --git a/code/datums/armor/_armor.dm b/code/datums/armor/_armor.dm
index 82a882c0527..c6dbf1d5fdd 100644
--- a/code/datums/armor/_armor.dm
+++ b/code/datums/armor/_armor.dm
@@ -126,11 +126,11 @@ GLOBAL_LIST_INIT(armor_by_type, generate_armor_type_cache())
 			new_armor.vars[mod] = value_all
 		return new_armor
 
-	for(var/value in values)
-		if(value in all_keys)
-			new_armor.vars[value] = values[value]
+	for(var/armor_rating in all_keys)
+		if(armor_rating in values)
+			new_armor.vars[armor_rating] = values[armor_rating]
 		else
-			stack_trace("Attempt to call generate_new_with_specific with illegal value '[value]'! Ignoring it")
+			new_armor.vars[armor_rating] = vars[armor_rating]
 	return new_armor
 
 /datum/armor/immune/generate_new_with_specific(list/values)
diff --git a/code/modules/unit_tests/_unit_tests.dm b/code/modules/unit_tests/_unit_tests.dm
index 73209b2505f..975c90f893d 100644
--- a/code/modules/unit_tests/_unit_tests.dm
+++ b/code/modules/unit_tests/_unit_tests.dm
@@ -83,6 +83,7 @@
 #include "anchored_mobs.dm"
 #include "anonymous_themes.dm"
 #include "area_contents.dm"
+#include "armor_verification.dm"
 #include "autowiki.dm"
 #include "barsigns.dm"
 #include "baseturfs.dm"
diff --git a/code/modules/unit_tests/armor_verification.dm b/code/modules/unit_tests/armor_verification.dm
new file mode 100644
index 00000000000..ef4613e49f1
--- /dev/null
+++ b/code/modules/unit_tests/armor_verification.dm
@@ -0,0 +1,33 @@
+/// Verifies that armor procs are working as expected
+/datum/unit_test/armor_verification
+
+/datum/unit_test/armor_verification/Run()
+	var/obj/dummy = allocate(/obj)
+
+	dummy.set_armor(/datum/armor/none)
+	var/datum/armor/armor = dummy.get_armor()
+	TEST_ASSERT_NOTNULL(armor, "armor didn't populate correctly when needed")
+	TEST_ASSERT_EQUAL(armor_totals(armor), 0, "none armor type had armor values")
+
+	armor = armor.generate_new_with_specific(list(FIRE = 20))
+	TEST_ASSERT_EQUAL(armor_totals(armor), 20, "modified armor type had incorrect values")
+
+	armor = armor.generate_new_with_specific(list(ACID = 20))
+	TEST_ASSERT_EQUAL(armor_totals(armor), 40, "modified armor type had incorrect values")
+
+	armor = get_armor_by_type(/datum/armor/immune)
+	var/totals = armor_totals(armor)
+	armor = armor.generate_new_with_multipliers(list(ARMOR_ALL = 0))
+	TEST_ASSERT_EQUAL(armor_totals(armor), totals, "modified an immune armor type")
+
+	var/wanted = 40
+	dummy.set_armor(/datum/armor/none)
+	dummy.set_armor_rating(ENERGY, wanted * 0.5)
+	dummy.set_armor_rating(FIRE, wanted * 0.5)
+	TEST_ASSERT_EQUAL(armor_totals(dummy.get_armor()), wanted, "modified armor type had incorrect values")
+
+/datum/unit_test/armor_verification/proc/armor_totals(datum/armor/armor)
+	var/total = 0
+	for(var/key in ARMOR_LIST_ALL())
+		total += armor.vars[key]
+	return total
diff --git a/code/modules/vehicles/mecha/_mecha.dm b/code/modules/vehicles/mecha/_mecha.dm
index 088dd0cb843..42b1a19879f 100644
--- a/code/modules/vehicles/mecha/_mecha.dm
+++ b/code/modules/vehicles/mecha/_mecha.dm
@@ -434,7 +434,7 @@
 	if(capacitor)
 		var/datum/armor/stock_armor = get_armor_by_type(armor_type)
 		var/initial_energy = stock_armor.get_rating(ENERGY)
-		set_armor_rating(initial_energy + (capacitor.rating * 5))
+		set_armor_rating(ENERGY, initial_energy + (capacitor.rating * 5))
 
 /obj/vehicle/sealed/mecha/examine(mob/user)
 	. = ..()