diff --git a/src/sound.cxx b/src/sound.cxx
index c4f7d68..83aecf1 100644
--- a/src/sound.cxx
+++ b/src/sound.cxx
@@ -158,7 +158,7 @@ out:
 
 void CSound::FlushAll ()
 {
-    for (int ch = 0; ch < sizeof (m_lpSDL); ++ch)
+    for (size_t ch = 0; ch < sizeof (m_lpSDL); ++ch)
         Flush (ch);
 }