diff --git a/src/de/craftinc/gates/GatesManager.java b/src/de/craftinc/gates/GatesManager.java
index 5af5228..5cebd5a 100644
--- a/src/de/craftinc/gates/GatesManager.java
+++ b/src/de/craftinc/gates/GatesManager.java
@@ -20,7 +20,9 @@ public class GatesManager
 {
 	private File gatesConfigFile;
 	private FileConfiguration gatesConfig;
-	private String gatesPath = "gates"; // path to gates inside the yaml file
+	private static final String gatesPath = "gates"; // path to gates inside the yaml file
+    private static final String storageVersionPath = "version";
+    private static final int storageVersion = 1;
 	
 	private Map<String, Gate> gatesById;
 	private Map<SimpleChunk, Set<Gate>> gatesByChunk;
@@ -52,6 +54,7 @@ public class GatesManager
 	public void saveGatesToDisk()
 	{
 		gatesConfig.set(gatesPath, new ArrayList<Object>(gatesById.values()));
+        gatesConfig.set(storageVersionPath, storageVersion);
 		
 		try {
 			gatesConfig.save(gatesConfigFile);
@@ -95,6 +98,14 @@ public class GatesManager
 		fillGatesByLocation();
 
         Plugin.log("Loaded " + this.gates.size() + " gates.");
+
+        // migration
+        int fileStorageVersion = gatesConfig.getInt(storageVersionPath);
+
+        if (fileStorageVersion < storageVersion) {
+            Plugin.log("Outdated storage version detected. Performing data migration...");
+            MigrationUtil.performMigration(fileStorageVersion, storageVersion, this.gates);
+        }
 	}
 	
 	
diff --git a/src/de/craftinc/gates/MigrationUtil.java b/src/de/craftinc/gates/MigrationUtil.java
new file mode 100644
index 0000000..e744efc
--- /dev/null
+++ b/src/de/craftinc/gates/MigrationUtil.java
@@ -0,0 +1,33 @@
+package de.craftinc.gates;
+
+import de.craftinc.gates.Gate;
+
+import org.bukkit.Location;
+import org.bukkit.Material;
+import org.bukkit.block.Block;
+
+import java.util.List;
+
+
+public class MigrationUtil
+{
+    public static void performMigration(int storageVersion, int currentVersion, List<Gate> gates)
+    {
+        if (currentVersion == 1 && storageVersion == 0) {
+
+            for (Gate g : gates) {
+
+                for (Location l : g.getGateBlockLocations()) {
+                    Block b = l.getBlock();
+
+                    if (b.getType() == Material.PORTAL) {
+                        b.setType(Material.AIR);
+                    }
+                }
+            }
+        }
+        else {
+            throw new IllegalArgumentException("Supplied storage version is currently not supported! Make sure you have the latest version of Craft Inc. Gates installed.");
+        }
+    }
+}