diff --git a/source/simulation2/components/CCmpPathfinder.cpp b/source/simulation2/components/CCmpPathfinder.cpp
index c1f2923825..eea299b971 100644
--- a/source/simulation2/components/CCmpPathfinder.cpp
+++ b/source/simulation2/components/CCmpPathfinder.cpp
@@ -470,6 +470,7 @@ void CCmpPathfinder::UpdateGrid()
 	{
 		m_MapSize = terrainSize;
 		m_Grid = new Grid<NavcellData>(m_MapSize * Pathfinding::NAVCELLS_PER_TILE, m_MapSize * Pathfinding::NAVCELLS_PER_TILE);
+		SAFE_DELETE(m_TerrainOnlyGrid);
 		m_TerrainOnlyGrid = new Grid<NavcellData>(m_MapSize * Pathfinding::NAVCELLS_PER_TILE, m_MapSize * Pathfinding::NAVCELLS_PER_TILE);
 
 		m_ObstructionsDirty = { true, true, true, Grid<u8>(m_MapSize * Pathfinding::NAVCELLS_PER_TILE, m_MapSize * Pathfinding::NAVCELLS_PER_TILE) };