diff --git a/src/arch/MemoryCard/MemoryCardDriverThreaded_MacOSX.cpp b/src/arch/MemoryCard/MemoryCardDriverThreaded_MacOSX.cpp
index 2107205a11..7c745beeb2 100644
--- a/src/arch/MemoryCard/MemoryCardDriverThreaded_MacOSX.cpp
+++ b/src/arch/MemoryCard/MemoryCardDriverThreaded_MacOSX.cpp
@@ -60,8 +60,25 @@ MemoryCardDriverThreaded_MacOSX::~MemoryCardDriverThreaded_MacOSX()
 
 void MemoryCardDriverThreaded_MacOSX::Unmount( UsbStorageDevice *pDevice )
 {
+#if defined(SYNC_VOLUME_FULLSYNC) && defined(SYNC_VOLUME_WAIT)
+	
 	if( sync_volume_np( pDevice->sOsMountDir.c_str(), SYNC_VOLUME_FULLSYNC | SYNC_VOLUME_WAIT ) != 0 )
 		LOG->Warn( "Failed to flush the memory card." );
+#else
+	ParamBlockRec pb;
+	Str255 name; // A pascal string.
+	const RString& base = Basename( pDevice->sOsMountDir );
+	
+	memset( &pb, 0, sizeof(pb) );
+	name[0] = min( base.length(), size_t(255) );
+	strncpy( (char *)&name[1], base, name[0] );
+	pb.volumeParam.ioNamePtr = name;
+	pb.volumeParam.ioVolIndex = -1; // Use ioNamePtr to find the volume.
+	
+	if( PBFlushVolSync(&pb) != noErr )
+		LOG->Warn( "Failed to flush the memory card." );
+	
+#endif
 }
 
 bool MemoryCardDriverThreaded_MacOSX::USBStorageDevicesChanged()