diff --git a/src/mapper/mapper.cc b/src/mapper/mapper.cc
index a33d59a..58c5ac7 100644
--- a/src/mapper/mapper.cc
+++ b/src/mapper/mapper.cc
@@ -17,6 +17,7 @@
 
 namespace fallout {
 
+static int categoryInit();
 static int categoryExit();
 static int categoryHide();
 static int categoryToggleState();
@@ -43,6 +44,12 @@ unsigned char* tool;
 // 0x6EC4AC
 int tool_win;
 
+// 0x4875B4
+int categoryInit()
+{
+    return 0;
+}
+
 // 0x487700
 int categoryExit()
 {