diff --git a/staging/src/k8s.io/apiextensions-apiserver/pkg/apiserver/schema/pruning/algorithm.go b/staging/src/k8s.io/apiextensions-apiserver/pkg/apiserver/schema/pruning/algorithm.go
index b7ed87b439e..b2b1bf81fbd 100644
--- a/staging/src/k8s.io/apiextensions-apiserver/pkg/apiserver/schema/pruning/algorithm.go
+++ b/staging/src/k8s.io/apiextensions-apiserver/pkg/apiserver/schema/pruning/algorithm.go
@@ -189,7 +189,7 @@ func skipPrune(x interface{}, s *structuralschema.Structural, opts *PruneOptions
 	case []interface{}:
 		for i, v := range x {
 			opts.appendIndex(i)
-			prune(v, s.Items, opts)
+			skipPrune(v, s.Items, opts)
 			opts.parentPath = opts.parentPath[:origPathLen]
 		}
 	default:
diff --git a/staging/src/k8s.io/apiextensions-apiserver/pkg/apiserver/schema/pruning/algorithm_test.go b/staging/src/k8s.io/apiextensions-apiserver/pkg/apiserver/schema/pruning/algorithm_test.go
index f050d3eb5f1..c7505478f5e 100644
--- a/staging/src/k8s.io/apiextensions-apiserver/pkg/apiserver/schema/pruning/algorithm_test.go
+++ b/staging/src/k8s.io/apiextensions-apiserver/pkg/apiserver/schema/pruning/algorithm_test.go
@@ -88,7 +88,8 @@ func TestPrune(t *testing.T) {
      "unspecified": "bar",
      "unspecifiedObject": {"unspecified": "bar"},
      "pruning": {"unspecified": "bar"},
-     "preserving": {"unspecified": "bar"}
+     "preserving": {"unspecified": "bar"},
+     "preservingUnknownType": [{"foo":true},{"bar":true}]
   },
   "preservingAdditionalPropertiesNotInheritingXPreserveUnknownFields": {
      "foo": {
@@ -129,6 +130,10 @@ func TestPrune(t *testing.T) {
 							Generic:    structuralschema.Generic{Type: "object"},
 							Extensions: structuralschema.Extensions{XPreserveUnknownFields: true},
 						},
+						"preservingUnknownType": {
+							Generic:    structuralschema.Generic{Type: ""},
+							Extensions: structuralschema.Extensions{XPreserveUnknownFields: true},
+						},
 						"pruning": {
 							Generic: structuralschema.Generic{Type: "object"},
 						},
@@ -177,7 +182,8 @@ func TestPrune(t *testing.T) {
      "unspecified": "bar",
      "unspecifiedObject": {"unspecified": "bar"},
      "pruning": {},
-     "preserving": {"unspecified": "bar"}
+     "preserving": {"unspecified": "bar"},
+     "preservingUnknownType": [{"foo":true},{"bar":true}]
   },
   "preservingAdditionalPropertiesNotInheritingXPreserveUnknownFields": {
      "foo": {