diff --git a/LEGO1/mxregion.cpp b/LEGO1/mxregion.cpp
index 44028f15..5ecc7b5d 100644
--- a/LEGO1/mxregion.cpp
+++ b/LEGO1/mxregion.cpp
@@ -105,10 +105,15 @@ void MxRegion::vtable1c()
   // TODO
 }
 
-// OFFSET: LEGO1 0x100c50e0 STUB
+// OFFSET: LEGO1 0x100c50e0
 MxRegionTopBottom::MxRegionTopBottom(MxRect32 &p_rect)
 {
+  m_top = p_rect.m_top;
+  m_bottom = p_rect.m_bottom;
+  m_leftRightList = new MxRegionLeftRightList;
 
+  MxRegionLeftRight *leftRight = new MxRegionLeftRight(p_rect.m_left, p_rect.m_right);
+  m_leftRightList->Append(leftRight);
 }
 
 // OFFSET: LEGO1 0x100c5280 STUB
diff --git a/LEGO1/mxregion.h b/LEGO1/mxregion.h
index 218584d5..f79c89f7 100644
--- a/LEGO1/mxregion.h
+++ b/LEGO1/mxregion.h
@@ -22,6 +22,12 @@ struct MxRegionTopBottom
 // SIZE 0x08
 struct MxRegionLeftRight
 {
+  MxRegionLeftRight(MxS32 p_left, MxS32 p_right)
+  {
+    m_left = p_left;
+    m_right = p_right;
+  }
+
   MxS32 m_left;
   MxS32 m_right;
 };