diff --git a/protobuf-api/src/main/java/com/google/protobuf/Descriptors.java b/protobuf-api/src/main/java/com/google/protobuf/Descriptors.java
index 23d43aa..4ac4e10 100644
--- a/protobuf-api/src/main/java/com/google/protobuf/Descriptors.java
+++ b/protobuf-api/src/main/java/com/google/protobuf/Descriptors.java
@@ -401,7 +401,7 @@ public static void internalBuildGeneratedFileFrom(
             "Invalid embedded descriptor for \"" + proto.getName() + "\".", e);
       }
 
-      final ExtensionRegistry registry = descriptorAssigner.assignDescriptors(result);
+      final ExtensionRegistryLite registry = descriptorAssigner.assignDescriptors(result);
 
       if (registry != null) {
         // We must re-parse the proto using the registry.
@@ -478,7 +478,7 @@ public static FileDescriptor internalBuildGeneratedFileFrom(
      * needed to recognize custom options.
      */
     public static void internalUpdateFileDescriptor(
-        FileDescriptor descriptor, ExtensionRegistry registry) {
+        FileDescriptor descriptor, ExtensionRegistryLite registry) {
       ByteString bytes = descriptor.proto.toByteString();
       try {
         FileDescriptorProto proto = FileDescriptorProto.parseFrom(bytes, registry);
@@ -504,7 +504,7 @@ public static void internalUpdateFileDescriptor(
      */
     @Deprecated
     public interface InternalDescriptorAssigner {
-      ExtensionRegistry assignDescriptors(FileDescriptor root);
+      ExtensionRegistryLite assignDescriptors(FileDescriptor root);
     }
 
     private FileDescriptorProto proto;
diff --git a/protobuf-api/src/main/java/com/google/protobuf/DynamicMessage.java b/protobuf-api/src/main/java/com/google/protobuf/DynamicMessage.java
index 578e362..aea63fb 100644
--- a/protobuf-api/src/main/java/com/google/protobuf/DynamicMessage.java
+++ b/protobuf-api/src/main/java/com/google/protobuf/DynamicMessage.java
@@ -71,7 +71,7 @@ public static DynamicMessage parseFrom(Descriptor type, CodedInputStream input)
 
   /** Parse a message of the given type from the given input stream. */
   public static DynamicMessage parseFrom(
-      Descriptor type, CodedInputStream input, ExtensionRegistry extensionRegistry)
+      Descriptor type, CodedInputStream input, ExtensionRegistryLite extensionRegistry)
       throws IOException {
     return newBuilder(type).mergeFrom(input, extensionRegistry).buildParsed();
   }
@@ -84,7 +84,7 @@ public static DynamicMessage parseFrom(Descriptor type, ByteString data)
 
   /** Parse {@code data} as a message of the given type and return it. */
   public static DynamicMessage parseFrom(
-      Descriptor type, ByteString data, ExtensionRegistry extensionRegistry)
+      Descriptor type, ByteString data, ExtensionRegistryLite extensionRegistry)
       throws InvalidProtocolBufferException {
     return newBuilder(type).mergeFrom(data, extensionRegistry).buildParsed();
   }
@@ -97,7 +97,7 @@ public static DynamicMessage parseFrom(Descriptor type, byte[] data)
 
   /** Parse {@code data} as a message of the given type and return it. */
   public static DynamicMessage parseFrom(
-      Descriptor type, byte[] data, ExtensionRegistry extensionRegistry)
+      Descriptor type, byte[] data, ExtensionRegistryLite extensionRegistry)
       throws InvalidProtocolBufferException {
     return newBuilder(type).mergeFrom(data, extensionRegistry).buildParsed();
   }
@@ -109,7 +109,7 @@ public static DynamicMessage parseFrom(Descriptor type, InputStream input) throw
 
   /** Parse a message of the given type from {@code input} and return it. */
   public static DynamicMessage parseFrom(
-      Descriptor type, InputStream input, ExtensionRegistry extensionRegistry) throws IOException {
+      Descriptor type, InputStream input, ExtensionRegistryLite extensionRegistry) throws IOException {
     return newBuilder(type).mergeFrom(input, extensionRegistry).buildParsed();
   }
 
diff --git a/protobuf-api/src/main/java/com/google/protobuf/FlattenedAbstractMessage.java b/protobuf-api/src/main/java/com/google/protobuf/FlattenedAbstractMessage.java
index df84945..b4dc588 100644
--- a/protobuf-api/src/main/java/com/google/protobuf/FlattenedAbstractMessage.java
+++ b/protobuf-api/src/main/java/com/google/protobuf/FlattenedAbstractMessage.java
@@ -640,7 +640,7 @@ BuilderType mergeFrom(final Message other, Map<FieldDescriptor, Object> allField
 
     @Override
     public BuilderType mergeFrom(final CodedInputStream input) throws IOException {
-      return mergeFrom(input, ExtensionRegistry.getEmptyRegistry());
+      return mergeFrom(input, ExtensionRegistryLite.getEmptyRegistry());
     }
 
     @Override
diff --git a/protobuf-api/src/main/java/com/google/protobuf/FlattenedGeneratedMessageV3.java b/protobuf-api/src/main/java/com/google/protobuf/FlattenedGeneratedMessageV3.java
index d51c6c6..08d54ed 100644
--- a/protobuf-api/src/main/java/com/google/protobuf/FlattenedGeneratedMessageV3.java
+++ b/protobuf-api/src/main/java/com/google/protobuf/FlattenedGeneratedMessageV3.java
@@ -1066,7 +1066,7 @@ BuilderT mergeFrom(final Message other, Map<FieldDescriptor, Object> allFields)
 
     @Override
     public BuilderT mergeFrom(final CodedInputStream input) throws IOException {
-      return mergeFrom(input, ExtensionRegistry.getEmptyRegistry());
+      return mergeFrom(input, ExtensionRegistryLite.getEmptyRegistry());
     }
 
     @Override
diff --git a/protobuf-api/src/main/java/com/google/protobuf/MapEntry.java b/protobuf-api/src/main/java/com/google/protobuf/MapEntry.java
index 8cc3622..0d21272 100644
--- a/protobuf-api/src/main/java/com/google/protobuf/MapEntry.java
+++ b/protobuf-api/src/main/java/com/google/protobuf/MapEntry.java
@@ -943,7 +943,7 @@ MapEntry.Builder<K,V> mergeFrom(final Message other, Map<FieldDescriptor, Object
 
     @Override
     public MapEntry.Builder<K,V> mergeFrom(final CodedInputStream input) throws IOException {
-      return mergeFrom(input, ExtensionRegistry.getEmptyRegistry());
+      return mergeFrom(input, ExtensionRegistryLite.getEmptyRegistry());
     }
 
     @Override
diff --git a/protobuf-api/src/main/java/com/google/protobuf/UnknownFieldSet.java b/protobuf-api/src/main/java/com/google/protobuf/UnknownFieldSet.java
index d87ad2b..967a06a 100644
--- a/protobuf-api/src/main/java/com/google/protobuf/UnknownFieldSet.java
+++ b/protobuf-api/src/main/java/com/google/protobuf/UnknownFieldSet.java
@@ -490,7 +490,7 @@ public boolean mergeFieldFrom(int tag, CodedInputStream input) throws IOExceptio
           return true;
         case WireFormat.WIRETYPE_START_GROUP:
           Builder subBuilder = newBuilder();
-          input.readGroup(number, subBuilder, ExtensionRegistry.getEmptyRegistry());
+          input.readGroup(number, subBuilder, ExtensionRegistryLite.getEmptyRegistry());
           getFieldBuilder(number).addGroup(subBuilder.build());
           return true;
         case WireFormat.WIRETYPE_END_GROUP: