diff --git a/system_scheduler.hpp b/system_scheduler.hpp
new file mode 100644
index 0000000..7644142
--- /dev/null
+++ b/system_scheduler.hpp
@@ -0,0 +1,52 @@
+#pragma once
+#include <functional>
+#include <vector> 
+
+namespace zecsy
+{
+    class system_scheduler final
+    {
+    public:
+        void add_system(float freq, auto&& func);
+
+        void add_system(int freq, auto&& func);
+
+        void update(float dt);
+
+    private:
+        struct system_handler
+        {
+            double interval;
+            double accumulator = 0.0f;
+            std::function<void(float)> callback;
+        };
+
+        std::vector<system_handler> systems;
+    };
+
+    inline void system_scheduler::add_system(float freq, auto&& func)
+    {
+        systems.emplace_back(1.0f / freq, 0.0f,
+                             std::forward<decltype(func)>(func));
+    }
+
+    inline void system_scheduler::add_system(int freq, auto&& func)
+    {
+        add_system(float(freq), func);
+    }
+
+    inline void system_scheduler::update(float dt)
+    {
+        dt = std::max(0.0f, dt);
+
+        for(auto& s: systems)
+        {
+            s.accumulator += dt;
+            while(s.accumulator >= s.interval)
+            {
+                s.callback(dt);
+                s.accumulator -= s.interval;
+            }
+        }
+    }
+} // namespace zecsy
diff --git a/tests/zecsy.cpp b/tests/zecsy.cpp
index a0fbc67..e3d3bea 100644
--- a/tests/zecsy.cpp
+++ b/tests/zecsy.cpp
@@ -3,6 +3,7 @@
 #include <catch2/catch_all.hpp>
 
 #include "../zecsy.hpp"
+#include "../system_scheduler.hpp"
 
 using namespace zecsy;
 
diff --git a/zecsy.hpp b/zecsy.hpp
index 325a78f..82b616e 100644
--- a/zecsy.hpp
+++ b/zecsy.hpp
@@ -1,10 +1,8 @@
 #pragma once
-#include <algorithm>
 #include <concepts>
 #include <cstdint>
 #include <cstdlib>
 #include <format>
-#include <functional>
 #include <set>
 #include <stdexcept>
 #include <type_traits>
@@ -29,52 +27,6 @@ namespace zecsy
         return true;
     }();
 
-    class system_scheduler final
-    {
-    public:
-        void add_system(float freq, auto&& func);
-
-        void add_system(int freq, auto&& func);
-
-        void update(float dt);
-
-    private:
-        struct system_handler
-        {
-            double interval;
-            double accumulator = 0.0f;
-            std::function<void(float)> callback;
-        };
-
-        std::vector<system_handler> systems;
-    };
-
-    inline void system_scheduler::add_system(float freq, auto&& func)
-    {
-        systems.emplace_back(1.0f / freq, 0.0f,
-                             std::forward<decltype(func)>(func));
-    }
-
-    inline void system_scheduler::add_system(int freq, auto&& func)
-    {
-        add_system(float(freq), func);
-    }
-
-    inline void system_scheduler::update(float dt)
-    {
-        dt = std::max(0.0f, dt);
-
-        for(auto& s: systems)
-        {
-            s.accumulator += dt;
-            while(s.accumulator >= s.interval)
-            {
-                s.callback(dt);
-                s.accumulator -= s.interval;
-            }
-        }
-    }
-
     class world final
     {
     public: