diff --git a/src/main/java/difflib/patch/ChangeDelta.java b/src/main/java/difflib/patch/ChangeDelta.java
index 3eed31c..10e8a52 100644
--- a/src/main/java/difflib/patch/ChangeDelta.java
+++ b/src/main/java/difflib/patch/ChangeDelta.java
@@ -39,11 +39,6 @@ public final class ChangeDelta<T> extends Delta<T> {
         super(DeltaType.CHANGE, original, revised);
     }
 
-    /**
-     * {@inheritDoc}
-     *
-     * @throws PatchFailedException
-     */
     @Override
     public void applyTo(List<T> target) throws PatchFailedException {
         verify(target);
@@ -59,9 +54,6 @@ public final class ChangeDelta<T> extends Delta<T> {
         }
     }
 
-    /**
-     * {@inheritDoc}
-     */
     @Override
     public void restore(List<T> target) {
         int position = getRevised().getPosition();
@@ -76,18 +68,6 @@ public final class ChangeDelta<T> extends Delta<T> {
         }
     }
 
-    /**
-     * {@inheritDoc}
-     */
-    @Override
-    public void verify(List<T> target) throws PatchFailedException {
-        getOriginal().verify(target);
-        if (getOriginal().getPosition() > target.size()) {
-            throw new PatchFailedException("Incorrect patch for delta: "
-                    + "delta original position > target size");
-        }
-    }
-
     @Override
     public String toString() {
         return "[ChangeDelta, position: " + getOriginal().getPosition() + ", lines: "
diff --git a/src/main/java/difflib/patch/Chunk.java b/src/main/java/difflib/patch/Chunk.java
index f2d5c61..5f6c8f5 100644
--- a/src/main/java/difflib/patch/Chunk.java
+++ b/src/main/java/difflib/patch/Chunk.java
@@ -68,7 +68,7 @@ public final class Chunk<T> {
      * @param target the sequence to verify against.
      */
     public void verify(List<T> target) throws PatchFailedException {
-        if (last() > target.size()) {
+        if (position > target.size() || last() > target.size()) {
             throw new PatchFailedException("Incorrect Chunk: the position of chunk > target size");
         }
         for (int i = 0; i < size(); i++) {
diff --git a/src/main/java/difflib/patch/DeleteDelta.java b/src/main/java/difflib/patch/DeleteDelta.java
index 396b7df..871a130 100644
--- a/src/main/java/difflib/patch/DeleteDelta.java
+++ b/src/main/java/difflib/patch/DeleteDelta.java
@@ -39,11 +39,6 @@ public final class DeleteDelta<T> extends Delta<T> {
         super(DeltaType.DELETE, original, revised);
     }
 
-    /**
-     * {@inheritDoc}
-     *
-     * @throws PatchFailedException
-     */
     @Override
     public void applyTo(List<T> target) throws PatchFailedException {
         verify(target);
@@ -53,10 +48,7 @@ public final class DeleteDelta<T> extends Delta<T> {
             target.remove(position);
         }
     }
-
-    /**
-     * {@inheritDoc}
-     */
+    
     @Override
     public void restore(List<T> target) {
         int position = this.getRevised().getPosition();
@@ -66,11 +58,6 @@ public final class DeleteDelta<T> extends Delta<T> {
         }
     }
 
-    @Override
-    public void verify(List<T> target) throws PatchFailedException {
-        getOriginal().verify(target);
-    }
-
     @Override
     public String toString() {
         return "[DeleteDelta, position: " + getOriginal().getPosition() + ", lines: "
diff --git a/src/main/java/difflib/patch/Delta.java b/src/main/java/difflib/patch/Delta.java
index d362627..baa40a9 100644
--- a/src/main/java/difflib/patch/Delta.java
+++ b/src/main/java/difflib/patch/Delta.java
@@ -79,7 +79,9 @@ public abstract class Delta<T> {
      * @param target the text to patch.
      * @throws PatchFailedException if the patch cannot be applied.
      */
-    public abstract void verify(List<T> target) throws PatchFailedException;
+    public void verify(List<T> target) throws PatchFailedException {
+        getOriginal().verify(target);
+    }
 
     /**
      * Applies this delta as the patch for a given target
diff --git a/src/main/java/difflib/patch/InsertDelta.java b/src/main/java/difflib/patch/InsertDelta.java
index 843620b..c9ae349 100644
--- a/src/main/java/difflib/patch/InsertDelta.java
+++ b/src/main/java/difflib/patch/InsertDelta.java
@@ -39,11 +39,6 @@ public final class InsertDelta<T> extends Delta<T> {
         super(DeltaType.INSERT, original, revised);
     }
 
-    /**
-     * {@inheritDoc}
-     *
-     * @throws PatchFailedException
-     */
     @Override
     public void applyTo(List<T> target) throws PatchFailedException {
         verify(target);
@@ -53,10 +48,7 @@ public final class InsertDelta<T> extends Delta<T> {
             target.add(position + i, lines.get(i));
         }
     }
-
-    /**
-     * {@inheritDoc}
-     */
+    
     @Override
     public void restore(List<T> target) {
         int position = getRevised().getPosition();
@@ -66,15 +58,6 @@ public final class InsertDelta<T> extends Delta<T> {
         }
     }
 
-    @Override
-    public void verify(List<T> target) throws PatchFailedException {
-        if (getOriginal().getPosition() > target.size()) {
-            throw new PatchFailedException("Incorrect patch for delta: "
-                    + "delta original position > target size");
-        }
-
-    }
-
     @Override
     public String toString() {
         return "[InsertDelta, position: " + getOriginal().getPosition()