diff --git a/src/core/System.cc b/src/core/System.cc
index c653b7c..14a7924 100644
--- a/src/core/System.cc
+++ b/src/core/System.cc
@@ -54,3 +54,8 @@ void * System::alloc_pages(int num)
             -1,
             0);
 }
+
+void System::free_pages(void * addr, int num)
+{
+    (void)munmap(addr, num << System::page_size_log);
+}
diff --git a/src/core/System.h b/src/core/System.h
index a37aeb2..764bac9 100644
--- a/src/core/System.h
+++ b/src/core/System.h
@@ -6,6 +6,7 @@ class System
 public:
     static bool init();
     static void * alloc_pages(int num);
+    static void free_pages(void * addr, int num);
 
     static unsigned long page_size;
     static unsigned int page_size_log;