diff --git a/src/com/sk89q/worldedit/WorldEdit.java b/src/com/sk89q/worldedit/WorldEdit.java
index 63665fbeb..094e17bce 100644
--- a/src/com/sk89q/worldedit/WorldEdit.java
+++ b/src/com/sk89q/worldedit/WorldEdit.java
@@ -41,6 +41,7 @@
 import com.sk89q.worldedit.tools.TraceTool;
 import com.sk89q.worldedit.masks.BlockTypeMask;
 import com.sk89q.worldedit.masks.ExistingBlockMask;
+import com.sk89q.worldedit.masks.InvertedBlockTypeMask;
 import com.sk89q.worldedit.masks.Mask;
 import com.sk89q.worldedit.patterns.*;
 
@@ -375,7 +376,12 @@ public Mask getBlockMask(LocalPlayer player, String list)
                 throw new UnknownItemException(list);
             }
         } else {
-            return new BlockTypeMask(getBlockIDs(player, list, true));
+            if (list.charAt(0) == '!' && list.length() > 1) {
+                return new InvertedBlockTypeMask(
+                        getBlockIDs(player, list.substring(1), true));
+            } else {
+                return new BlockTypeMask(getBlockIDs(player, list, true));
+            }
         }
     }
 
diff --git a/src/com/sk89q/worldedit/masks/InvertedBlockTypeMask.java b/src/com/sk89q/worldedit/masks/InvertedBlockTypeMask.java
new file mode 100644
index 000000000..009cd8766
--- /dev/null
+++ b/src/com/sk89q/worldedit/masks/InvertedBlockTypeMask.java
@@ -0,0 +1,54 @@
+// $Id$
+/*
+ * WorldEdit
+ * Copyright (C) 2010, 2011 sk89q <http://www.sk89q.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+package com.sk89q.worldedit.masks;
+
+import java.util.Set;
+import com.sk89q.worldedit.EditSession;
+import com.sk89q.worldedit.Vector;
+
+/**
+ * A block type mask that only matches blocks that are not in the list.
+ *
+ * @author sk89q
+ */
+public class InvertedBlockTypeMask extends BlockTypeMask {
+    public InvertedBlockTypeMask() {
+    }
+
+    /**
+     * @param types
+     */
+    public InvertedBlockTypeMask(Set<Integer> types) {
+        super(types);
+    }
+
+    /**
+     * @param type
+     */
+    public InvertedBlockTypeMask(int type) {
+        super(type);
+    }
+
+    @Override
+    public boolean matches(EditSession editSession, Vector pos) {
+        return !types.contains(editSession.getBlockType(pos));
+    }
+
+}