diff --git a/media/libstagefright/id3/ID3.cpp b/media/libstagefright/id3/ID3.cpp
index 792a68afcd..425468f41f 100644
--- a/media/libstagefright/id3/ID3.cpp
+++ b/media/libstagefright/id3/ID3.cpp
@@ -32,7 +32,7 @@ namespace android {
 
 static const size_t kMaxMetadataSize = 3 * 1024 * 1024;
 
-struct MemorySource : public DataSourceBase {
+struct ID3::MemorySource : public DataSourceBase {
     MemorySource(const uint8_t *data, size_t size)
         : mData(data),
           mSize(size) {
@@ -58,7 +58,7 @@ private:
     DISALLOW_EVIL_CONSTRUCTORS(MemorySource);
 };
 
-class DataSourceUnwrapper : public DataSourceBase {
+class ID3::DataSourceUnwrapper : public DataSourceBase {
 
 public:
     explicit DataSourceUnwrapper(DataSourceHelper *sourcehelper) {
diff --git a/media/libstagefright/include/ID3.h b/media/libstagefright/include/ID3.h
index 5e433ea699..2843a7a39c 100644
--- a/media/libstagefright/include/ID3.h
+++ b/media/libstagefright/include/ID3.h
@@ -77,6 +77,8 @@ struct ID3 {
     size_t rawSize() const { return mRawSize; }
 
 private:
+    class DataSourceUnwrapper;
+    struct MemorySource;
     bool mIsValid;
     uint8_t *mData;
     size_t mSize;