diff --git a/include/gqueue/gqueue.h b/include/gqueue/gqueue.h
index 44a42247..b590846c 100644
--- a/include/gqueue/gqueue.h
+++ b/include/gqueue/gqueue.h
@@ -206,9 +206,9 @@ bool_t gfxQueueFSyncIsEmpty(gfxQueueFSync *pqueue);
  * @api
  * @{
  */
-bool_t gfxQueueASyncIsIn(gfxQueueASync *pqueue, gfxQueueASyncItem *pitem);
-bool_t gfxQueueGSyncIsIn(gfxQueueGSync *pqueue, gfxQueueGSyncItem *pitem);
-bool_t gfxQueueFSyncIsIn(gfxQueueFSync *pqueue, gfxQueueFSyncItem *pitem);
+bool_t gfxQueueASyncIsIn(gfxQueueASync *pqueue, const gfxQueueASyncItem *pitem);
+bool_t gfxQueueGSyncIsIn(gfxQueueGSync *pqueue, const gfxQueueGSyncItem *pitem);
+bool_t gfxQueueFSyncIsIn(gfxQueueFSync *pqueue, const gfxQueueFSyncItem *pitem);
 /* @} */
 
 /**
diff --git a/src/gqueue/gqueue.c b/src/gqueue/gqueue.c
index f73c43df..7a4c0b7e 100644
--- a/src/gqueue/gqueue.c
+++ b/src/gqueue/gqueue.c
@@ -75,7 +75,7 @@
 	bool_t gfxQueueASyncIsEmpty(gfxQueueASync *pqueue) {
 		return pqueue->head == NULL;
 	}
-	bool_t gfxQueueASyncIsIn(gfxQueueASync *pqueue, gfxQueueASyncItem *pitem) {
+	bool_t gfxQueueASyncIsIn(gfxQueueASync *pqueue, const gfxQueueASyncItem *pitem) {
 		gfxQueueASyncItem *pi;
 
 		gfxSystemLock();
@@ -156,7 +156,7 @@
 	bool_t gfxQueueGSyncIsEmpty(gfxQueueGSync *pqueue) {
 		return pqueue->head == NULL;
 	}
-	bool_t gfxQueueGSyncIsIn(gfxQueueGSync *pqueue, gfxQueueGSyncItem *pitem) {
+	bool_t gfxQueueGSyncIsIn(gfxQueueGSync *pqueue, const gfxQueueGSyncItem *pitem) {
 		gfxQueueGSyncItem *pi;
 
 		gfxSystemLock();
@@ -248,7 +248,7 @@
 	bool_t gfxQueueFSyncIsEmpty(gfxQueueFSync *pqueue) {
 		return pqueue->head == NULL;
 	}
-	bool_t gfxQueueFSyncIsIn(gfxQueueFSync *pqueue, gfxQueueFSyncItem *pitem) {
+	bool_t gfxQueueFSyncIsIn(gfxQueueFSync *pqueue, const gfxQueueFSyncItem *pitem) {
 		gfxQueueASyncItem *pi;
 
 		gfxSystemLock();