diff --git a/solver/llbsolver/ops/exec.go b/solver/llbsolver/ops/exec.go
index 0e2e8a8f4..078aa8b7b 100644
--- a/solver/llbsolver/ops/exec.go
+++ b/solver/llbsolver/ops/exec.go
@@ -10,13 +10,13 @@ import (
 	"os"
 	"path"
 	"path/filepath"
-	"runtime"
 	"sort"
 	"strings"
 	"sync"
 	"time"
 
 	"github.com/containerd/containerd/mount"
+	"github.com/containerd/containerd/platforms"
 	"github.com/docker/docker/pkg/locker"
 	"github.com/moby/buildkit/cache"
 	"github.com/moby/buildkit/cache/metadata"
@@ -34,6 +34,7 @@ import (
 	utilsystem "github.com/moby/buildkit/util/system"
 	"github.com/moby/buildkit/worker"
 	digest "github.com/opencontainers/go-digest"
+	specs "github.com/opencontainers/image-spec/specs-go/v1"
 	"github.com/opencontainers/runc/libcontainer/system"
 	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
@@ -51,12 +52,13 @@ type execOp struct {
 	md        *metadata.Store
 	exec      executor.Executor
 	w         worker.Worker
+	platform  *pb.Platform
 	numInputs int
 
 	cacheMounts map[string]*cacheRefShare
 }
 
-func NewExecOp(v solver.Vertex, op *pb.Op_Exec, cm cache.Manager, sm *session.Manager, md *metadata.Store, exec executor.Executor, w worker.Worker) (solver.Op, error) {
+func NewExecOp(v solver.Vertex, op *pb.Op_Exec, platform *pb.Platform, cm cache.Manager, sm *session.Manager, md *metadata.Store, exec executor.Executor, w worker.Worker) (solver.Op, error) {
 	return &execOp{
 		op:          op.Exec,
 		cm:          cm,
@@ -65,6 +67,7 @@ func NewExecOp(v solver.Vertex, op *pb.Op_Exec, cm cache.Manager, sm *session.Ma
 		exec:        exec,
 		numInputs:   len(v.Inputs()),
 		w:           w,
+		platform:    platform,
 		cacheMounts: map[string]*cacheRefShare{},
 	}, nil
 }
@@ -98,16 +101,27 @@ func (e *execOp) CacheMap(ctx context.Context, index int) (*solver.CacheMap, boo
 	}
 	op.Meta.ProxyEnv = nil
 
+	p := platforms.DefaultSpec()
+	if e.platform != nil {
+		p = specs.Platform{
+			OS:           e.platform.OS,
+			Architecture: e.platform.Architecture,
+			Variant:      e.platform.Variant,
+		}
+	}
+
 	dt, err := json.Marshal(struct {
-		Type string
-		Exec *pb.ExecOp
-		OS   string
-		Arch string
+		Type    string
+		Exec    *pb.ExecOp
+		OS      string
+		Arch    string
+		Variant string `json:",omitempty"`
 	}{
-		Type: execCacheType,
-		Exec: &op,
-		OS:   runtime.GOOS,
-		Arch: runtime.GOARCH,
+		Type:    execCacheType,
+		Exec:    &op,
+		OS:      p.OS,
+		Arch:    p.Architecture,
+		Variant: p.Variant,
 	})
 	if err != nil {
 		return nil, false, err
diff --git a/worker/base/worker.go b/worker/base/worker.go
index 1926d50f7..fe7c64fb8 100644
--- a/worker/base/worker.go
+++ b/worker/base/worker.go
@@ -197,7 +197,7 @@ func (w *Worker) ResolveOp(v solver.Vertex, s frontend.FrontendLLBBridge, sm *se
 		case *pb.Op_Source:
 			return ops.NewSourceOp(v, op, baseOp.Platform, w.SourceManager, sm, w)
 		case *pb.Op_Exec:
-			return ops.NewExecOp(v, op, w.CacheManager, sm, w.MetadataStore, w.Executor, w)
+			return ops.NewExecOp(v, op, baseOp.Platform, w.CacheManager, sm, w.MetadataStore, w.Executor, w)
 		case *pb.Op_Build:
 			return ops.NewBuildOp(v, op, s, w)
 		}