diff --git a/Minecraft.World/WorldGen/Biomes/FixedBiomeSource.cpp b/Minecraft.World/WorldGen/Biomes/FixedBiomeSource.cpp
index 8952a9ea4..a9ccbe062 100644
--- a/Minecraft.World/WorldGen/Biomes/FixedBiomeSource.cpp
+++ b/Minecraft.World/WorldGen/Biomes/FixedBiomeSource.cpp
@@ -200,7 +200,7 @@ TilePos* FixedBiomeSource::findBiome(int x, int z, int r, Biome* toFind,
  * @brief Finds a biome from a list of allowed biomes randomly.
  */
 TilePos* FixedBiomeSource::findBiome(int x, int z, int r,
-                                     const std::vector<Biome*>& allowed,
+                                     const std::vector<Biome*> allowed,
                                      Random* random) {
     if (find(allowed.begin(), allowed.end(), biome) != allowed.end()) {
         return new TilePos(x - r + random->nextInt(r * 2 + 1), 0,
@@ -220,6 +220,6 @@ bool FixedBiomeSource::containsOnly(int x, int z, int r, Biome* allowed) {
  * @brief Checks if the fixed biome is in the allowed list.
  */
 bool FixedBiomeSource::containsOnly(int x, int z, int r,
-                                    const std::vector<Biome*>& allowed) {
+                                    const std::vector<Biome*> allowed) {
     return find(allowed.begin(), allowed.end(), biome) != allowed.end();
 }
diff --git a/Minecraft.World/WorldGen/Biomes/FixedBiomeSource.h b/Minecraft.World/WorldGen/Biomes/FixedBiomeSource.h
index fea35d8dc..1836d4292 100644
--- a/Minecraft.World/WorldGen/Biomes/FixedBiomeSource.h
+++ b/Minecraft.World/WorldGen/Biomes/FixedBiomeSource.h
@@ -36,10 +36,10 @@ class FixedBiomeSource : public BiomeSource {
     virtual TilePos* findBiome(int x, int z, int r, Biome* toFind,
                                Random* random);
     virtual TilePos* findBiome(int x, int z, int r,
-                               const std::vector<Biome*>& allowed,
+                               const std::vector<Biome*> allowed,
                                Random* random);
     virtual bool containsOnly(int x, int z, int r, Biome* allowed);
     virtual bool containsOnly(
         int x, int z, int r,
-        const std::vector<Biome*>& allowed);
+        const std::vector<Biome*> allowed);
 };