diff --git a/src/main/java/com/sun/syndication/feed/CopyFrom.java b/src/main/java/com/sun/syndication/feed/CopyFrom.java
index dfd35ea..db126de 100644
--- a/src/main/java/com/sun/syndication/feed/CopyFrom.java
+++ b/src/main/java/com/sun/syndication/feed/CopyFrom.java
@@ -46,6 +46,6 @@ public interface CopyFrom<T> {
      * @param obj the instance to copy properties from.
      * 
      */
-    public void copyFrom(CopyFrom<T> obj);
+    public void copyFrom(CopyFrom<? extends T> obj);
 
 }
diff --git a/src/main/java/com/sun/syndication/feed/module/DCModuleImpl.java b/src/main/java/com/sun/syndication/feed/module/DCModuleImpl.java
index 5894ba3..d88cfa9 100644
--- a/src/main/java/com/sun/syndication/feed/module/DCModuleImpl.java
+++ b/src/main/java/com/sun/syndication/feed/module/DCModuleImpl.java
@@ -1051,7 +1051,7 @@ public class DCModuleImpl extends ModuleImpl implements DCModule {
     }
 
     @Override
-    public final void copyFrom(final CopyFrom<Module> obj) {
+    public final void copyFrom(final CopyFrom<? extends Module> obj) {
         COPY_FROM_HELPER.copy(this, obj);
     }
 
diff --git a/src/main/java/com/sun/syndication/feed/module/DCSubjectImpl.java b/src/main/java/com/sun/syndication/feed/module/DCSubjectImpl.java
index 240be0b..2d1b71f 100644
--- a/src/main/java/com/sun/syndication/feed/module/DCSubjectImpl.java
+++ b/src/main/java/com/sun/syndication/feed/module/DCSubjectImpl.java
@@ -161,7 +161,7 @@ public class DCSubjectImpl implements Cloneable, Serializable, DCSubject {
     }
 
     @Override
-    public void copyFrom(final CopyFrom<DCSubject> obj) {
+    public void copyFrom(final CopyFrom<? extends DCSubject> obj) {
         COPY_FROM_HELPER.copy(this, obj);
     }
 
diff --git a/src/main/java/com/sun/syndication/feed/module/SyModuleImpl.java b/src/main/java/com/sun/syndication/feed/module/SyModuleImpl.java
index 3ba798b..86b8bdd 100644
--- a/src/main/java/com/sun/syndication/feed/module/SyModuleImpl.java
+++ b/src/main/java/com/sun/syndication/feed/module/SyModuleImpl.java
@@ -145,7 +145,7 @@ public class SyModuleImpl extends ModuleImpl implements SyModule {
     }
 
     @Override
-    public void copyFrom(final CopyFrom<Module> obj) {
+    public void copyFrom(final CopyFrom<? extends Module> obj) {
         COPY_FROM_HELPER.copy(this, obj);
     }
 
diff --git a/src/main/java/com/sun/syndication/feed/synd/SyndContentImpl.java b/src/main/java/com/sun/syndication/feed/synd/SyndContentImpl.java
index ce0f074..e009f53 100644
--- a/src/main/java/com/sun/syndication/feed/synd/SyndContentImpl.java
+++ b/src/main/java/com/sun/syndication/feed/synd/SyndContentImpl.java
@@ -184,7 +184,7 @@ public class SyndContentImpl implements Serializable, SyndContent {
     }
 
     @Override
-    public void copyFrom(final CopyFrom<SyndContent> obj) {
+    public void copyFrom(final CopyFrom<? extends SyndContent> obj) {
         COPY_FROM_HELPER.copy(this, obj);
     }
 
diff --git a/src/main/java/com/sun/syndication/feed/synd/SyndEnclosureImpl.java b/src/main/java/com/sun/syndication/feed/synd/SyndEnclosureImpl.java
index 0e66cc1..d3d7aa5 100644
--- a/src/main/java/com/sun/syndication/feed/synd/SyndEnclosureImpl.java
+++ b/src/main/java/com/sun/syndication/feed/synd/SyndEnclosureImpl.java
@@ -154,7 +154,7 @@ public class SyndEnclosureImpl implements Serializable, SyndEnclosure {
     }
 
     @Override
-    public void copyFrom(final CopyFrom<SyndEnclosure> obj) {
+    public void copyFrom(final CopyFrom<? extends SyndEnclosure> obj) {
         COPY_FROM_HELPER.copy(this, obj);
     }
 
diff --git a/src/main/java/com/sun/syndication/feed/synd/SyndEntryImpl.java b/src/main/java/com/sun/syndication/feed/synd/SyndEntryImpl.java
index 0075ee4..acf631e 100644
--- a/src/main/java/com/sun/syndication/feed/synd/SyndEntryImpl.java
+++ b/src/main/java/com/sun/syndication/feed/synd/SyndEntryImpl.java
@@ -495,7 +495,7 @@ public class SyndEntryImpl implements Serializable, SyndEntry {
     }
 
     @Override
-    public void copyFrom(final CopyFrom<SyndEntry> obj) {
+    public void copyFrom(final CopyFrom<? extends SyndEntry> obj) {
         COPY_FROM_HELPER.copy(this, obj);
     }
 
diff --git a/src/main/java/com/sun/syndication/feed/synd/SyndFeedImpl.java b/src/main/java/com/sun/syndication/feed/synd/SyndFeedImpl.java
index ef8efee..0cc66dd 100644
--- a/src/main/java/com/sun/syndication/feed/synd/SyndFeedImpl.java
+++ b/src/main/java/com/sun/syndication/feed/synd/SyndFeedImpl.java
@@ -788,7 +788,7 @@ public class SyndFeedImpl implements Serializable, SyndFeed {
     }
 
     @Override
-    public void copyFrom(final CopyFrom<SyndFeed> obj) {
+    public void copyFrom(final CopyFrom<? extends SyndFeed> obj) {
         COPY_FROM_HELPER.copy(this, obj);
     }
 
diff --git a/src/main/java/com/sun/syndication/feed/synd/SyndImageImpl.java b/src/main/java/com/sun/syndication/feed/synd/SyndImageImpl.java
index 84059ce..42f8135 100644
--- a/src/main/java/com/sun/syndication/feed/synd/SyndImageImpl.java
+++ b/src/main/java/com/sun/syndication/feed/synd/SyndImageImpl.java
@@ -205,7 +205,7 @@ public class SyndImageImpl implements Serializable, SyndImage {
     }
 
     @Override
-    public void copyFrom(final CopyFrom<SyndImage> syndImage) {
+    public void copyFrom(final CopyFrom<? extends SyndImage> syndImage) {
         COPY_FROM_HELPER.copy(this, syndImage);
     }