diff --git a/src/main/java/gregtech/common/blocks/GT_Block_Ores_GC.java b/src/main/java/gregtech/common/blocks/GT_Block_Ores_GC.java
index c70b302a..23061baa 100644
--- a/src/main/java/gregtech/common/blocks/GT_Block_Ores_GC.java
+++ b/src/main/java/gregtech/common/blocks/GT_Block_Ores_GC.java
@@ -16,6 +16,8 @@ public class GT_Block_Ores_GC extends GT_Block_Ores_Abstract {
 
     public GT_Block_Ores_GC() {
         super("gt.blockores.gc", 4, true, Material.rock);
+        if (aMoonBlock == null) aMoonBlock = Blocks.stone;
+        if (aMarsBlock == null) aMarsBlock = Blocks.stone;
     }
 
     @Override