diff --git a/src/mapgen/mapgen.cpp b/src/mapgen/mapgen.cpp
index f537b8b7ad..24cf140dbf 100644
--- a/src/mapgen/mapgen.cpp
+++ b/src/mapgen/mapgen.cpp
@@ -774,9 +774,13 @@ void MapgenBasic::removeOvergeneratedCStone()
 	for (s16 z = node_min.Z; z <= node_max.Z; z++)
 	for (s16 x = node_min.X; x <= node_max.X; x++) {
 		u32 vi = vm->m_area.index(x, node_max.Y + 1, z); // top
-		vm->m_data[vi].setContent(CONTENT_IGNORE);
+		if (vm->m_data[vi].getContent() == c_stone) {
+			vm->m_data[vi].setContent(CONTENT_IGNORE);
+		}
 		vi = vm->m_area.index(x, node_min.Y - 1, z);     // bottom
-		vm->m_data[vi].setContent(CONTENT_IGNORE);
+		if (vm->m_data[vi].getContent() == c_stone) {
+			vm->m_data[vi].setContent(CONTENT_IGNORE);
+		}
 	}
 }
 
diff --git a/src/mapgen/mapgen_v6.cpp b/src/mapgen/mapgen_v6.cpp
index c3c75f5033..bb73cc8a78 100644
--- a/src/mapgen/mapgen_v6.cpp
+++ b/src/mapgen/mapgen_v6.cpp
@@ -631,9 +631,13 @@ void MapgenV6::removeOvergeneratedCStone()
 	for (s16 z = node_min.Z; z <= node_max.Z; z++)
 	for (s16 x = node_min.X; x <= node_max.X; x++) {
 		u32 vi = vm->m_area.index(x, node_max.Y + 1, z); // top
-		vm->m_data[vi].setContent(CONTENT_IGNORE);
+		if (vm->m_data[vi].getContent() == c_stone) {
+			vm->m_data[vi].setContent(CONTENT_IGNORE);
+		}
 		vi = vm->m_area.index(x, node_min.Y - 1, z);     // bottom
-		vm->m_data[vi].setContent(CONTENT_IGNORE);
+		if (vm->m_data[vi].getContent() == c_stone) {
+			vm->m_data[vi].setContent(CONTENT_IGNORE);
+		}
 	}
 }