diff --git a/src/disaster_cmd.cpp b/src/disaster_cmd.cpp
--- a/src/disaster_cmd.cpp
+++ b/src/disaster_cmd.cpp
@@ -48,6 +48,9 @@
 #include "table/strings.h"
 #include "table/sprites.h"
 
+/** Delay counter for considering the next disaster. */
+uint16 _disaster_delay;
+
 enum DisasterSubType {
 	ST_ZEPPELINER,
 	ST_ZEPPELINER_SHADOW,
diff --git a/src/saveload/misc_sl.cpp b/src/saveload/misc_sl.cpp
--- a/src/saveload/misc_sl.cpp
+++ b/src/saveload/misc_sl.cpp
@@ -26,6 +26,8 @@
 #include "saveload.h"
 
 extern TileIndex _cur_tileloop_tile;
+extern uint16 _disaster_delay;
+extern byte _trees_tick_ctr;
 
 /* Keep track of current game position */
 int _saved_scrollpos_x;
diff --git a/src/saveload/oldloader_sl.cpp b/src/saveload/oldloader_sl.cpp
--- a/src/saveload/oldloader_sl.cpp
+++ b/src/saveload/oldloader_sl.cpp
@@ -1552,6 +1552,8 @@ static bool LoadTTDPatchExtraChunks(Load
 }
 
 extern TileIndex _cur_tileloop_tile;
+extern uint16 _disaster_delay;
+extern byte _trees_tick_ctr;
 static const OldChunks main_chunk[] = {
 	OCL_ASSERT( OC_TTD, 0 ),
 	OCL_ASSERT( OC_TTO, 0 ),
diff --git a/src/tree_cmd.cpp b/src/tree_cmd.cpp
--- a/src/tree_cmd.cpp
+++ b/src/tree_cmd.cpp
@@ -52,6 +52,8 @@ enum ExtraTreePlacement {
 	ETP_ALL,        ///< Place trees on all tiles
 };
 
+/** Determines when to consider building more trees. */
+byte _trees_tick_ctr;
 
 /**
  * Tests if a tile can be converted to MP_TREES
diff --git a/src/variables.h b/src/variables.h
--- a/src/variables.h
+++ b/src/variables.h
@@ -19,12 +19,6 @@
 /* Amount of game ticks */
 VARDEF uint16 _tick_counter;
 
-/* Also save scrollpos_x, scrollpos_y and zoom */
-VARDEF uint16 _disaster_delay;
-
-/* Determines how often to run the tree loop */
-VARDEF byte _trees_tick_ctr;
-
 /* NOSAVE: Used in palette animations only, not really important. */
 VARDEF int _palette_animation_counter;