diff --git a/src/landscape.cpp b/src/landscape.cpp
index 871067e8cf..dfc4d88387 100644
--- a/src/landscape.cpp
+++ b/src/landscape.cpp
@@ -35,10 +35,10 @@
 #include "town.h"
 #include "3rdparty/cpp-btree/btree_set.h"
 #include "scope_info.h"
+#include "core/ring_buffer.hpp"
 #include <array>
 #include <list>
 #include <set>
-#include <deque>
 
 #include "table/strings.h"
 #include "table/sprites.h"
@@ -1359,7 +1359,7 @@ static bool FlowRiver(TileIndex spring, TileIndex begin, uint min_river_length)
 	SET_MARK(begin);
 
 	/* Breadth first search for the closest tile we can flow down to. */
-	std::deque<TileIndex> queue;
+	ring_buffer<TileIndex> queue;
 	queue.push_back(begin);
 
 	bool found = false;
diff --git a/src/map.cpp b/src/map.cpp
index 1c2e35abe9..ce820b8d48 100644
--- a/src/map.cpp
+++ b/src/map.cpp
@@ -15,8 +15,8 @@
 #include "rail_map.h"
 #include "tunnelbridge_map.h"
 #include "3rdparty/cpp-btree/btree_map.h"
+#include "core/ring_buffer.hpp"
 #include <array>
-#include <deque>
 #include <memory>
 
 #if defined(__linux__)
@@ -442,7 +442,7 @@ bool EnoughContiguousTilesMatchingCondition(TileIndex tile, uint threshold, Test
 	static_assert(MAX_MAP_TILES_BITS <= 30);
 
 	btree::btree_set<uint32> processed_tiles;
-	std::deque<uint32> candidates;
+	ring_buffer<uint32> candidates;
 	uint matching_count = 0;
 
 	auto process_tile = [&](TileIndex t, DiagDirection exclude_onward_dir) {