diff --git a/rtengine/guidedfilter.cc b/rtengine/guidedfilter.cc
index 4e31fa300..790245b20 100644
--- a/rtengine/guidedfilter.cc
+++ b/rtengine/guidedfilter.cc
@@ -215,7 +215,7 @@ void guidedFilter(const array2D<float> &guide, const array2D<float> &src, array2
     f_upsample(meanA, meana);
     DEBUG_DUMP(meanA);
 
-    array2D<float> &meanB = q;
+    array2D<float> meanB(W, H);
     f_upsample(meanB, meanb);
     DEBUG_DUMP(meanB);