diff --git a/pkg/gotd/mtproxy/faketls/ccs_test.go b/pkg/gotd/mtproxy/faketls/ccs_test.go
new file mode 100644
index 00000000..07b7e990
--- /dev/null
+++ b/pkg/gotd/mtproxy/faketls/ccs_test.go
@@ -0,0 +1,65 @@
+package faketls
+
+import (
+	"bytes"
+	"io"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+// TestReadSkipsChangeCipherSpec ensures interleaved ChangeCipherSpec records
+// do not pollute the Application-data stream. Earlier behaviour wrote the
+// 1-byte CCS payload into readBuf, which desynced the obfuscated2 CTR
+// keystream and produced "msg_key is invalid" on decrypted MTProto messages.
+func TestReadSkipsChangeCipherSpec(t *testing.T) {
+	a := require.New(t)
+
+	wire := bytes.NewBuffer(nil)
+
+	// CCS record (1 byte = 0x01)
+	_, err := writeRecord(wire, record{
+		Type:    RecordTypeChangeCipherSpec,
+		Version: Version12Bytes,
+		Data:    []byte{0x01},
+	})
+	a.NoError(err)
+
+	// Application record carrying our payload
+	payload := []byte("hello-mtproto-bytes")
+	_, err = writeRecord(wire, record{
+		Type:    RecordTypeApplication,
+		Version: Version12Bytes,
+		Data:    payload,
+	})
+	a.NoError(err)
+
+	// Another CCS in the middle
+	_, err = writeRecord(wire, record{
+		Type:    RecordTypeChangeCipherSpec,
+		Version: Version12Bytes,
+		Data:    []byte{0x01},
+	})
+	a.NoError(err)
+
+	// Second application record
+	more := []byte("second-payload")
+	_, err = writeRecord(wire, record{
+		Type:    RecordTypeApplication,
+		Version: Version12Bytes,
+		Data:    more,
+	})
+	a.NoError(err)
+
+	tls := NewFakeTLS(zeroReader{}, &readonly{r: wire})
+
+	got, err := io.ReadAll(io.LimitReader(tls, int64(len(payload)+len(more))))
+	a.NoError(err)
+	a.Equal(append(append([]byte(nil), payload...), more...), got)
+}
+
+// readonly adapts an io.Reader to io.ReadWriter (NewFakeTLS demands one).
+type readonly struct{ r io.Reader }
+
+func (r *readonly) Read(p []byte) (int, error)  { return r.r.Read(p) }
+func (r *readonly) Write(p []byte) (int, error) { return len(p), nil }
diff --git a/pkg/gotd/mtproxy/faketls/faketls.go b/pkg/gotd/mtproxy/faketls/faketls.go
index feb78569..d8bd5c59 100644
--- a/pkg/gotd/mtproxy/faketls/faketls.go
+++ b/pkg/gotd/mtproxy/faketls/faketls.go
@@ -93,20 +93,27 @@ func (o *FakeTLS) Read(b []byte) (n int, err error) {
 		return o.readBuf.Read(b)
 	}
 
-	rec, err := readRecord(o.conn)
-	if err != nil {
-		return 0, errors.Wrap(err, "read TLS record")
-	}
+	// Skip ChangeCipherSpec records — they are TLS-level keep-alive /
+	// compatibility markers (one-byte payload 0x01) and must NOT be
+	// passed up to the obfuscated2 layer, otherwise the CTR keystream
+	// position desyncs and subsequent MTProto messages decrypt to
+	// garbage (`msg_key is invalid`).
+	for {
+		rec, err := readRecord(o.conn)
+		if err != nil {
+			return 0, errors.Wrap(err, "read TLS record")
+		}
 
-	switch rec.Type {
-	case RecordTypeChangeCipherSpec:
-	case RecordTypeApplication:
-	case RecordTypeHandshake:
-		return 0, errors.New("unexpected record type handshake")
-	default:
-		return 0, errors.Errorf("unsupported record type %v", rec.Type)
+		switch rec.Type {
+		case RecordTypeChangeCipherSpec:
+			continue
+		case RecordTypeApplication:
+			o.readBuf.Write(rec.Data)
+			return o.readBuf.Read(b)
+		case RecordTypeHandshake:
+			return 0, errors.New("unexpected record type handshake")
+		default:
+			return 0, errors.Errorf("unsupported record type %v", rec.Type)
+		}
 	}
-	o.readBuf.Write(rec.Data)
-
-	return o.readBuf.Read(b)
 }