diff --git a/src/osgPlugins/ffmpeg/FFmpegDecoder.hpp b/src/osgPlugins/ffmpeg/FFmpegDecoder.hpp
index f6c83e714..43bc9475a 100644
--- a/src/osgPlugins/ffmpeg/FFmpegDecoder.hpp
+++ b/src/osgPlugins/ffmpeg/FFmpegDecoder.hpp
@@ -103,8 +103,8 @@ protected:
     AVStream *            m_audio_stream;
     AVStream *            m_video_stream;
 
-    unsigned int        m_audio_index;
-    unsigned int        m_video_index;
+    int                 m_audio_index;
+    int                 m_video_index;
 
     FFmpegClocks        m_clocks;
     FFmpegPacket        m_pending_packet;