diff --git a/paper-server/src/main/java/org/bukkit/craftbukkit/tag/CraftBlockTag.java b/paper-server/src/main/java/org/bukkit/craftbukkit/tag/CraftBlockTag.java
index df180227e1..e3f746589a 100644
--- a/paper-server/src/main/java/org/bukkit/craftbukkit/tag/CraftBlockTag.java
+++ b/paper-server/src/main/java/org/bukkit/craftbukkit/tag/CraftBlockTag.java
@@ -17,7 +17,14 @@ public class CraftBlockTag extends CraftTag<Block, Material> {
 
     @Override
     public boolean isTagged(Material item) {
-        return CraftMagicNumbers.getBlock(item).builtInRegistryHolder().is(tag);
+        Block block = CraftMagicNumbers.getBlock(item);
+
+        // SPIGOT-6952: A Material is not necessary a block, in this case return false
+        if (block == null) {
+            return false;
+        }
+
+        return block.builtInRegistryHolder().is(tag);
     }
 
     @Override
diff --git a/paper-server/src/main/java/org/bukkit/craftbukkit/tag/CraftItemTag.java b/paper-server/src/main/java/org/bukkit/craftbukkit/tag/CraftItemTag.java
index 3a5bcbc811..24e6130f21 100644
--- a/paper-server/src/main/java/org/bukkit/craftbukkit/tag/CraftItemTag.java
+++ b/paper-server/src/main/java/org/bukkit/craftbukkit/tag/CraftItemTag.java
@@ -17,7 +17,14 @@ public class CraftItemTag extends CraftTag<Item, Material> {
 
     @Override
     public boolean isTagged(Material item) {
-        return CraftMagicNumbers.getItem(item).builtInRegistryHolder().is(tag);
+        Item minecraft = CraftMagicNumbers.getItem(item);
+
+        // SPIGOT-6952: A Material is not necessary an item, in this case return false
+        if (minecraft == null) {
+            return false;
+        }
+
+        return minecraft.builtInRegistryHolder().is(tag);
     }
 
     @Override