diff --git a/libswscale/ops.c b/libswscale/ops.c
index 09e97c8120..1220f70c42 100644
--- a/libswscale/ops.c
+++ b/libswscale/ops.c
@@ -472,6 +472,11 @@ void ff_sws_op_list_update_comps(SwsOpList *ops)
         SwsOp *op = &ops->ops[n];
         bool need_in[4] = { false, false, false, false };
 
+        for (int i = 0; i < 4; i++) {
+            if (!need_out[i])
+                op->comps.flags[i] = SWS_COMP_GARBAGE;
+        }
+
         switch (op->op) {
         case SWS_OP_READ:
         case SWS_OP_WRITE:
diff --git a/tests/ref/fate/sws-ops-list b/tests/ref/fate/sws-ops-list
index 4385d809e7..cafa68665d 100644
--- a/tests/ref/fate/sws-ops-list
+++ b/tests/ref/fate/sws-ops-list
@@ -1 +1 @@
-e5a6788fa43852d75544e7fb6ae7744d
+da5cdcd09fffb274b454a64f1d95b073