diff --git a/builder/builder-next/controller.go b/builder/builder-next/controller.go
index e740a76583..4b33412ba4 100644
--- a/builder/builder-next/controller.go
+++ b/builder/builder-next/controller.go
@@ -8,6 +8,7 @@ import (
 	"github.com/containerd/containerd/content/local"
 	"github.com/containerd/containerd/platforms"
 	"github.com/docker/docker/api/types"
+	"github.com/docker/docker/api/types/filters"
 	"github.com/docker/docker/builder/builder-next/adapters/containerimage"
 	"github.com/docker/docker/builder/builder-next/adapters/localinlinecache"
 	"github.com/docker/docker/builder/builder-next/adapters/snapshot"
@@ -232,7 +233,7 @@ func getGCPolicy(conf config.BuilderConfig, root string) ([]client.PruneInfo, er
 				gcPolicy[i], err = toBuildkitPruneInfo(types.BuildCachePruneOptions{
 					All:         p.All,
 					KeepStorage: b,
-					Filters:     p.Filter,
+					Filters:     filters.Args(p.Filter),
 				})
 				if err != nil {
 					return nil, err
diff --git a/daemon/config/builder.go b/daemon/config/builder.go
index ac85e76b30..5b774d2f07 100644
--- a/daemon/config/builder.go
+++ b/daemon/config/builder.go
@@ -1,12 +1,38 @@
 package config
 
-import "github.com/docker/docker/api/types/filters"
+import (
+	"encoding/json"
+	"strings"
+
+	"github.com/docker/docker/api/types/filters"
+)
 
 // BuilderGCRule represents a GC rule for buildkit cache
 type BuilderGCRule struct {
-	All         bool         `json:",omitempty"`
-	Filter      filters.Args `json:",omitempty"`
-	KeepStorage string       `json:",omitempty"`
+	All         bool            `json:",omitempty"`
+	Filter      BuilderGCFilter `json:",omitempty"`
+	KeepStorage string          `json:",omitempty"`
+}
+
+type BuilderGCFilter filters.Args
+
+func (x *BuilderGCFilter) UnmarshalJSON(data []byte) error {
+	var arr []string
+	f := filters.NewArgs()
+	if err := json.Unmarshal(data, &arr); err != nil {
+		// backwards compat for deprecated buggy form
+		err := json.Unmarshal(data, &f)
+		*x = BuilderGCFilter(f)
+		return err
+	}
+	for _, s := range arr {
+		fields := strings.SplitN(s, "=", 2)
+		name := strings.ToLower(strings.TrimSpace(fields[0]))
+		value := strings.TrimSpace(fields[1])
+		f.Add(name, value)
+	}
+	*x = BuilderGCFilter(f)
+	return nil
 }
 
 // BuilderGCConfig contains GC config for a buildkit builder
diff --git a/daemon/config/builder_test.go b/daemon/config/builder_test.go
new file mode 100644
index 0000000000..db3225fdd0
--- /dev/null
+++ b/daemon/config/builder_test.go
@@ -0,0 +1,44 @@
+package config
+
+import (
+	"testing"
+
+	"github.com/docker/docker/api/types/filters"
+	"github.com/google/go-cmp/cmp"
+	"gotest.tools/assert"
+	"gotest.tools/fs"
+)
+
+func TestBuilderGC(t *testing.T) {
+	tempFile := fs.NewFile(t, "config", fs.WithContent(`{
+  "builder": {
+    "gc": {
+      "enabled": true,
+      "policy": [
+        {"keepStorage": "10GB", "filter": ["unused-for=2200h"]},
+        {"keepStorage": "50GB", "filter": {"unused-for": {"3300h": true}}},
+        {"keepStorage": "100GB", "all": true}
+      ]
+    }
+  }
+}`))
+	defer tempFile.Remove()
+	configFile := tempFile.Path()
+
+	cfg, err := MergeDaemonConfigurations(&Config{}, nil, configFile)
+	assert.NilError(t, err)
+	assert.Assert(t, cfg.Builder.GC.Enabled)
+	f1 := filters.NewArgs()
+	f1.Add("unused-for", "2200h")
+	f2 := filters.NewArgs()
+	f2.Add("unused-for", "3300h")
+	expectedPolicy := []BuilderGCRule{
+		{KeepStorage: "10GB", Filter: BuilderGCFilter(f1)},
+		{KeepStorage: "50GB", Filter: BuilderGCFilter(f2)}, /* parsed from deprecated form */
+		{KeepStorage: "100GB", All: true},
+	}
+	assert.DeepEqual(t, cfg.Builder.GC.Policy, expectedPolicy, cmp.AllowUnexported(BuilderGCFilter{}))
+	// double check to please the skeptics
+	assert.Assert(t, filters.Args(cfg.Builder.GC.Policy[0].Filter).UniqueExactMatch("unused-for", "2200h"))
+	assert.Assert(t, filters.Args(cfg.Builder.GC.Policy[1].Filter).UniqueExactMatch("unused-for", "3300h"))
+}