diff --git a/src/source/TetrisRogue.cpp b/src/source/TetrisRogue.cpp
index 3cbfbca..f580882 100644
--- a/src/source/TetrisRogue.cpp
+++ b/src/source/TetrisRogue.cpp
@@ -411,6 +411,7 @@ static int GetUpgradeBaseRarity(int upgradeId)
     case UPGRADE_CROSS_PIECE:
     case UPGRADE_BLACK_HOLE:
     case UPGRADE_AIR_RESHAPE:
+    case UPGRADE_RAINBOW_PIECE:
     case UPGRADE_STABLE_STRUCTURE:
     case UPGRADE_DOUBLE_GROWTH:
         return UPGRADE_RARITY_UNCOMMON;