diff --git a/ot_mutex.c b/ot_mutex.c
index 5624c03..fb632d7 100644
--- a/ot_mutex.c
+++ b/ot_mutex.c
@@ -194,7 +194,7 @@ ot_taskid mutex_workqueue_poptask( ot_tasktype *tasktype ) {
   while( !taskid ) {
     /* Skip to the first unassigned task this worker wants to do */
     task = tasklist;
-    while( task && ( ( ( TASK_MASK & task->tasktype ) != *tasktype ) || task->taskid ) )
+    while( task && ( ( ( TASK_CLASS_MASK & task->tasktype ) != *tasktype ) || task->taskid ) )
       task = task->next;
 
     /* If we found an outstanding task, assign a taskid to it
diff --git a/ot_mutex.h b/ot_mutex.h
index fd45397..e2106be 100644
--- a/ot_mutex.h
+++ b/ot_mutex.h
@@ -40,7 +40,13 @@ typedef enum {
   TASK_DMEM                        = 0x0500,
 
   TASK_DONE                        = 0x0f00,
-  TASK_MASK                        = 0xff00
+
+  TASK_FLAG_GZIP                   = 0x1000,
+  TASK_FLAG_BZIP2                  = 0x2000,
+
+  TASK_TASK_MASK                   = 0x0fff,
+  TASK_CLASS_MASK                  = 0x0f00,
+  TASK_FLAGS_MASK                  = 0xf000
 } ot_tasktype;
 
 typedef unsigned long ot_taskid;