diff --git a/code/ATMOSPHERICS/components/binary_devices/dp_vent_pump.dm b/code/ATMOSPHERICS/components/binary_devices/dp_vent_pump.dm
index 4267baf4cd..c0cf15616f 100644
--- a/code/ATMOSPHERICS/components/binary_devices/dp_vent_pump.dm
+++ b/code/ATMOSPHERICS/components/binary_devices/dp_vent_pump.dm
@@ -8,8 +8,6 @@
 #define PRESSURE_CHECK_INPUT 2
 #define PRESSURE_CHECK_OUTPUT 4
 
-#undefine
-
 /obj/machinery/atmospherics/binary/dp_vent_pump
 	icon = 'icons/atmos/vent_pump.dmi'
 	icon_state = "map_dp_vent"
@@ -258,4 +256,14 @@
 
 	spawn(2)
 		broadcast_status()
-	update_icon()
\ No newline at end of file
+	update_icon()
+
+#undef DEFAULT_PRESSURE_DELTA
+
+#undef EXTERNAL_PRESSURE_BOUND
+#undef INTERNAL_PRESSURE_BOUND
+#undef PRESSURE_CHECKS
+
+#undef PRESSURE_CHECK_EXTERNAL
+#undef PRESSURE_CHECK_INPUT
+#undef PRESSURE_CHECK_OUTPUT
diff --git a/code/ATMOSPHERICS/components/binary_devices/passive_gate.dm b/code/ATMOSPHERICS/components/binary_devices/passive_gate.dm
index 00a8abe50a..6a51dc41b1 100644
--- a/code/ATMOSPHERICS/components/binary_devices/passive_gate.dm
+++ b/code/ATMOSPHERICS/components/binary_devices/passive_gate.dm
@@ -2,8 +2,6 @@
 #define REGULATE_INPUT	1	//shuts off when input side is below the target pressure
 #define REGULATE_OUTPUT	2	//shuts off when output side is above the target pressure
 
-#undefine
-
 /obj/machinery/atmospherics/binary/passive_gate
 	icon = 'icons/atmos/passive_gate.dmi'
 	icon_state = "map"
@@ -259,3 +257,7 @@
 			"You hear ratchet.")
 		new /obj/item/pipe(loc, make_from=src)
 		qdel(src)
+
+#undef REGULATE_NONE
+#undef REGULATE_INPUT
+#undef REGULATE_OUTPUT
diff --git a/code/ATMOSPHERICS/components/unary/vent_pump.dm b/code/ATMOSPHERICS/components/unary/vent_pump.dm
index dd0292d3ad..5d5a3496f9 100644
--- a/code/ATMOSPHERICS/components/unary/vent_pump.dm
+++ b/code/ATMOSPHERICS/components/unary/vent_pump.dm
@@ -7,8 +7,6 @@
 #define PRESSURE_CHECK_EXTERNAL 1
 #define PRESSURE_CHECK_INTERNAL 2
 
-#undefine
-
 /obj/machinery/atmospherics/unary/vent_pump
 	icon = 'icons/atmos/vent_pump.dmi'
 	icon_state = "map_vent"
@@ -424,3 +422,12 @@
 		initial_loc.air_vent_names -= id_tag
 	..()
 	return
+
+#undef DEFAULT_PRESSURE_DELTA
+
+#undef EXTERNAL_PRESSURE_BOUND
+#undef INTERNAL_PRESSURE_BOUND
+#undef PRESSURE_CHECKS
+
+#undef PRESSURE_CHECK_EXTERNAL
+#undef PRESSURE_CHECK_INTERNAL
diff --git a/code/game/machinery/door_control.dm b/code/game/machinery/door_control.dm
index 7829897e72..8916beb413 100644
--- a/code/game/machinery/door_control.dm
+++ b/code/game/machinery/door_control.dm
@@ -92,7 +92,6 @@
 #define BOLTS  0x4
 #define SHOCK  0x8
 #define SAFE   0x10
-#undefine
 
 /obj/machinery/button/remote/airlock
 	name = "remote door-control"
@@ -138,6 +137,12 @@
 				if(specialfunctions & SAFE)
 					D.set_safeties(1)
 
+#undef OPEN
+#undef IDSCAN
+#undef BOLTS
+#undef SHOCK
+#undef SAFE
+
 /*
 	Blast door remote control
 */
diff --git a/code/game/mecha/equipment/tools/tools.dm b/code/game/mecha/equipment/tools/tools.dm
index 55e2f92f1b..4b9a17483f 100644
--- a/code/game/mecha/equipment/tools/tools.dm
+++ b/code/game/mecha/equipment/tools/tools.dm
@@ -1158,7 +1158,6 @@
 
 #define LOCKED 1
 #define OCCUPIED 2
-#undefine
 
 /obj/mecha/proc/move_inside_passenger()
 	set category = "Object"
@@ -1211,3 +1210,6 @@
 			usr << "<span class='danger'>All of the passenger compartments are already occupied or locked!</span>"
 		if (0)
 			usr << "<span class='warning'>\The [src] doesn't have a passenger compartment.</span>"
+
+#undef LOCKED
+#undef OCCUPIED