diff --git a/src/clear_map.h b/src/clear_map.h
--- a/src/clear_map.h
+++ b/src/clear_map.h
@@ -267,7 +267,7 @@ static inline void MakeClear(TileIndex t
 	_m[t].m3 = 0;
 	_m[t].m4 = 0 << 5 | 0 << 2;
 	SetClearGroundDensity(t, g, density); // Sets m5
-	_m[t].m6 = 0;
+	_me[t].m6 = 0;
 	_me[t].m7 = 0;
 }
 
diff --git a/src/map_type.h b/src/map_type.h
--- a/src/map_type.h
+++ b/src/map_type.h
@@ -24,7 +24,6 @@ struct Tile {
 	byte   m3;          ///< General purpose
 	byte   m4;          ///< General purpose
 	byte   m5;          ///< General purpose
-	byte   m6;          ///< General purpose
 };
 
 /**
diff --git a/src/misc_gui.cpp b/src/misc_gui.cpp
--- a/src/misc_gui.cpp
+++ b/src/misc_gui.cpp
@@ -130,7 +130,7 @@ public:
 		DEBUG(misc, LANDINFOD_LEVEL, "m3     = %#x", _m[tile].m3);
 		DEBUG(misc, LANDINFOD_LEVEL, "m4     = %#x", _m[tile].m4);
 		DEBUG(misc, LANDINFOD_LEVEL, "m5     = %#x", _m[tile].m5);
-		DEBUG(misc, LANDINFOD_LEVEL, "m6     = %#x", _m[tile].m6);
+		DEBUG(misc, LANDINFOD_LEVEL, "m6     = %#x", _me[tile].m6);
 		DEBUG(misc, LANDINFOD_LEVEL, "m7     = %#x", _me[tile].m7);
 #undef LANDINFOD_LEVEL
 	}