diff --git a/src/mapgen/mapgen.h b/src/mapgen/mapgen.h
index de18fdd45d..b3dadd7b7d 100644
--- a/src/mapgen/mapgen.h
+++ b/src/mapgen/mapgen.h
@@ -12,6 +12,7 @@
 #include "util/string.h"
 #include "util/container.h"
 #include <utility>
+#include <set>
 
 #define MAPGEN_DEFAULT MAPGEN_V7
 #define MAPGEN_DEFAULT_NAME "v7"
diff --git a/src/server/activeobjectmgr.h b/src/server/activeobjectmgr.h
index 9c65ad514e..739dc6a777 100644
--- a/src/server/activeobjectmgr.h
+++ b/src/server/activeobjectmgr.h
@@ -6,6 +6,7 @@
 
 #include <functional>
 #include <vector>
+#include <set>
 #include "../activeobjectmgr.h"
 #include "serveractiveobject.h"
 #include "util/k_d_tree.h"
diff --git a/src/util/container.h b/src/util/container.h
index 88cb772d26..180d3eebfc 100644
--- a/src/util/container.h
+++ b/src/util/container.h
@@ -12,7 +12,7 @@
 #include <list>
 #include <vector>
 #include <map>
-#include <set>
+#include <unordered_set>
 #include <queue>
 #include <cassert>
 #include <limits>
@@ -32,7 +32,7 @@ public:
 	true: value added
 	false: value already exists
 	*/
-	bool push_back(const Value& value)
+	bool push_back(const Value &value)
 	{
 		if (m_set.insert(value).second)
 		{
@@ -48,7 +48,7 @@ public:
 		m_queue.pop();
 	}
 
-	const Value& front() const
+	const Value &front() const
 	{
 		return m_queue.front();
 	}
@@ -64,7 +64,7 @@ public:
 	}
 
 private:
-	std::set<Value> m_set;
+	std::unordered_set<Value> m_set;
 	std::queue<Value> m_queue;
 };