diff --git a/src/mapper/mapper.cc b/src/mapper/mapper.cc
index 24d3fe3..97c9b42 100644
--- a/src/mapper/mapper.cc
+++ b/src/mapper/mapper.cc
@@ -17,6 +17,7 @@
 
 namespace fallout {
 
+static void bookmarkHide();
 static void bookmarkUnHide();
 static int categoryInit();
 static int categoryExit();
@@ -48,6 +49,14 @@ unsigned char* tool;
 // 0x6EC4AC
 int tool_win;
 
+// 0x4875E0
+void bookmarkHide()
+{
+    if (bookmarkWin != -1) {
+        windowHide(bookmarkWin);
+    }
+}
+
 // 0x4875F8
 void bookmarkUnHide()
 {