1 files changed, 1 insertions, 1 deletions

diff --git a/src/Generating/PieceStructuresGen.h b/src/Generating/PieceStructuresGen.h
index f0449a9b3..c3d7c4ee3 100644
--- a/src/Generating/PieceStructuresGen.h
+++ b/src/Generating/PieceStructuresGen.h
@@ -34,7 +34,7 @@ public:
 	a_Prefabs contains the list of prefab sets that should be activated, "|"-separated.
 	All problems are logged to the console and the generator skips over them.
 	Returns true if at least one prefab set is valid (the generator should be kept). */
-	bool Initialize(const AString & a_Prefabs, int a_SeaLevel, cBiomeGenPtr a_BiomeGen, cTerrainHeightGenPtr a_HeightGen);
+	bool Initialize(const AString & a_Prefabs, int a_SeaLevel, const cBiomeGenPtr & a_BiomeGen, const cTerrainHeightGenPtr & a_HeightGen);
 
 	// cFinishGen override:
 	virtual void GenFinish(cChunkDesc & a_ChunkDesc) override;