diff --git a/libfreerdp/codec/progressive.c b/libfreerdp/codec/progressive.c
index 03ad76677..754979fc3 100644
--- a/libfreerdp/codec/progressive.c
+++ b/libfreerdp/codec/progressive.c
@@ -1626,7 +1626,7 @@ struct _PROGRESSIVE_TILE_PROCESS_WORK_PARAM
 {
 	PROGRESSIVE_CONTEXT* progressive;
 	PROGRESSIVE_BLOCK_REGION* region;
-	PROGRESSIVE_BLOCK_CONTEXT* context;
+	const PROGRESSIVE_BLOCK_CONTEXT* context;
 	RFX_PROGRESSIVE_TILE* tile;
 };
 typedef struct _PROGRESSIVE_TILE_PROCESS_WORK_PARAM PROGRESSIVE_TILE_PROCESS_WORK_PARAM;