diff --git a/worldguard-bukkit/src/main/java/com/sk89q/worldguard/bukkit/util/Materials.java b/worldguard-bukkit/src/main/java/com/sk89q/worldguard/bukkit/util/Materials.java
index b5b7dd3a..35b7ce93 100644
--- a/worldguard-bukkit/src/main/java/com/sk89q/worldguard/bukkit/util/Materials.java
+++ b/worldguard-bukkit/src/main/java/com/sk89q/worldguard/bukkit/util/Materials.java
@@ -1646,6 +1646,8 @@ public static boolean isToolApplicable(Material toolMaterial, Material targetMat
             case RED_DYE:
             case WHITE_DYE:
             case YELLOW_DYE:
+            case GLOW_INK_SAC:
+            case INK_SAC:
                 return Tag.SIGNS.isTagged(targetMaterial);
             case HONEYCOMB:
                 return isUnwaxedCopper(targetMaterial);