diff --git a/encode_test.go b/encode_test.go
index 98f71b0..83075c5 100644
--- a/encode_test.go
+++ b/encode_test.go
@@ -2086,3 +2086,25 @@ func TestIssue263(t *testing.T) {
 		t.Fatalf("expected:[%s] but got:[%s]", string(expected), string(actual))
 	}
 }
+
+func TestEmbeddedNotFirstField(t *testing.T) {
+	type Embedded struct {
+		Has bool `json:"has"`
+	}
+	type T struct {
+		X        int `json:"is"`
+		Embedded `json:"child"`
+	}
+	p := T{X: 10, Embedded: Embedded{Has: true}}
+	expected, err := stdjson.Marshal(&p)
+	if err != nil {
+		t.Fatal(err)
+	}
+	got, err := json.Marshal(&p)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !bytes.Equal(expected, got) {
+		t.Fatalf("failed to encode embedded structure. expected = %q but got %q", expected, got)
+	}
+}
diff --git a/internal/cmd/generator/vm.go.tmpl b/internal/cmd/generator/vm.go.tmpl
index f2c992a..5c62354 100644
--- a/internal/cmd/generator/vm.go.tmpl
+++ b/internal/cmd/generator/vm.go.tmpl
@@ -3439,7 +3439,7 @@ func Run(ctx *encoder.RuntimeContext, b []byte, codeSet *encoder.OpcodeSet) ([]b
 				code = code.Next
 			}
 		case encoder.OpStructField:
-			if code.Flags&encoder.AnonymousKeyFlags == 0 {
+			if code.Flags&encoder.IsTaggedKeyFlags != 0 || code.Flags&encoder.AnonymousKeyFlags == 0 {
 				b = appendStructKey(ctx, code, b)
 			}
 			p := load(ctxptr, code.Idx) + uintptr(code.Offset)
diff --git a/internal/encoder/vm/vm.go b/internal/encoder/vm/vm.go
index f2c992a..5c62354 100644
--- a/internal/encoder/vm/vm.go
+++ b/internal/encoder/vm/vm.go
@@ -3439,7 +3439,7 @@ func Run(ctx *encoder.RuntimeContext, b []byte, codeSet *encoder.OpcodeSet) ([]b
 				code = code.Next
 			}
 		case encoder.OpStructField:
-			if code.Flags&encoder.AnonymousKeyFlags == 0 {
+			if code.Flags&encoder.IsTaggedKeyFlags != 0 || code.Flags&encoder.AnonymousKeyFlags == 0 {
 				b = appendStructKey(ctx, code, b)
 			}
 			p := load(ctxptr, code.Idx) + uintptr(code.Offset)
diff --git a/internal/encoder/vm_color/vm.go b/internal/encoder/vm_color/vm.go
index 70de3e7..71aa3f7 100644
--- a/internal/encoder/vm_color/vm.go
+++ b/internal/encoder/vm_color/vm.go
@@ -3439,7 +3439,7 @@ func Run(ctx *encoder.RuntimeContext, b []byte, codeSet *encoder.OpcodeSet) ([]b
 				code = code.Next
 			}
 		case encoder.OpStructField:
-			if code.Flags&encoder.AnonymousKeyFlags == 0 {
+			if code.Flags&encoder.IsTaggedKeyFlags != 0 || code.Flags&encoder.AnonymousKeyFlags == 0 {
 				b = appendStructKey(ctx, code, b)
 			}
 			p := load(ctxptr, code.Idx) + uintptr(code.Offset)
diff --git a/internal/encoder/vm_color_indent/vm.go b/internal/encoder/vm_color_indent/vm.go
index 2d014e5..60d0083 100644
--- a/internal/encoder/vm_color_indent/vm.go
+++ b/internal/encoder/vm_color_indent/vm.go
@@ -3439,7 +3439,7 @@ func Run(ctx *encoder.RuntimeContext, b []byte, codeSet *encoder.OpcodeSet) ([]b
 				code = code.Next
 			}
 		case encoder.OpStructField:
-			if code.Flags&encoder.AnonymousKeyFlags == 0 {
+			if code.Flags&encoder.IsTaggedKeyFlags != 0 || code.Flags&encoder.AnonymousKeyFlags == 0 {
 				b = appendStructKey(ctx, code, b)
 			}
 			p := load(ctxptr, code.Idx) + uintptr(code.Offset)
diff --git a/internal/encoder/vm_indent/vm.go b/internal/encoder/vm_indent/vm.go
index 25d2ebc..e817484 100644
--- a/internal/encoder/vm_indent/vm.go
+++ b/internal/encoder/vm_indent/vm.go
@@ -3439,7 +3439,7 @@ func Run(ctx *encoder.RuntimeContext, b []byte, codeSet *encoder.OpcodeSet) ([]b
 				code = code.Next
 			}
 		case encoder.OpStructField:
-			if code.Flags&encoder.AnonymousKeyFlags == 0 {
+			if code.Flags&encoder.IsTaggedKeyFlags != 0 || code.Flags&encoder.AnonymousKeyFlags == 0 {
 				b = appendStructKey(ctx, code, b)
 			}
 			p := load(ctxptr, code.Idx) + uintptr(code.Offset)