diff --git a/src/biome.cpp b/src/biome.cpp
index 180a9c4a5..34d51839f 100644
--- a/src/biome.cpp
+++ b/src/biome.cpp
@@ -127,7 +127,7 @@ void BiomeDefManager::addBiome(Biome *b) {
 	bgroup->push_back(b);
 
 	verbosestream << "BiomeDefManager: added biome '" << b->name <<
-		"' to biome group " << b->groupid << std::endl;
+		"' to biome group " << (int)b->groupid << std::endl;
 }