diff --git a/src/sna/sna.h b/src/sna/sna.h
index 27f5708c..76599fe4 100644
--- a/src/sna/sna.h
+++ b/src/sna/sna.h
@@ -208,7 +208,7 @@ struct sna_gc {
 	long changes;
 	long serial;
 
-	GCFuncs *old_funcs;
+	const GCFuncs *old_funcs;
 	void *priv;
 };
 
diff --git a/src/sna/sna_accel.c b/src/sna/sna_accel.c
index 36ad9b32..abfc0527 100644
--- a/src/sna/sna_accel.c
+++ b/src/sna/sna_accel.c
@@ -4068,7 +4068,7 @@ static void sna_gc_move_to_gpu(GCPtr gc)
 	assert(gc->funcs == (GCFuncs *)&sna_gc_funcs__cpu);
 
 	gc->ops = (GCOps *)&sna_gc_ops;
-	gc->funcs = sna_gc(gc)->old_funcs;
+	gc->funcs = (GCFuncs *)sna_gc(gc)->old_funcs;
 	assert(gc->funcs);
 	gc->pCompositeClip = sna_gc(gc)->priv;
 	assert(gc->pCompositeClip);