diff --git a/src/filter/ConvertFilterPlugin.cxx b/src/filter/ConvertFilterPlugin.cxx
index 23c912b05..6a5acd707 100644
--- a/src/filter/ConvertFilterPlugin.cxx
+++ b/src/filter/ConvertFilterPlugin.cxx
@@ -34,11 +34,6 @@
 struct ConvertFilter {
 	struct filter base;
 
-	/**
-	 * The current convert, from 0 to #PCM_CONVERT_1.
-	 */
-	unsigned convert;
-
 	/**
 	 * The input audio format; PCM data is passed to the filter()
 	 * method in this format.