diff --git a/sdk/sdk.go b/sdk/sdk.go
index 30a64c519b..7baaf297db 100644
--- a/sdk/sdk.go
+++ b/sdk/sdk.go
@@ -136,6 +136,9 @@ func buildKASClient(c *config) (KASClient, error) {
 
 // Close closes the underlying grpc.ClientConn.
 func (s SDK) Close() error {
+	if s.conn == nil {
+		return nil
+	}
 	if err := s.conn.Close(); err != nil {
 		return errors.Join(ErrShutdownFailed, err)
 	}
@@ -147,7 +150,7 @@ func (s SDK) Conn() *grpc.ClientConn {
 	return s.conn
 }
 
-// ExchangeToken exchanges a access token for a new token. https://datatracker.ietf.org/doc/html/rfc8693
+// TokenExchange exchanges a access token for a new token. https://datatracker.ietf.org/doc/html/rfc8693
 func (s SDK) TokenExchange(token string) (string, error) {
 	return "", nil
 }
diff --git a/sdk/tdf.go b/sdk/tdf.go
index a3985db908..bb31dc7eeb 100644
--- a/sdk/tdf.go
+++ b/sdk/tdf.go
@@ -81,7 +81,7 @@ type Unwrapper interface {
 }
 
 // CreateTDF reads plain text from the given reader and saves it to the writer, subject to the given options
-func (sdk SDK) CreateTDF(writer io.Writer, reader io.ReadSeeker, opts ...TDFOption) (*TDFObject, error) { //nolint:funlen, gocognit, lll
+func (s SDK) CreateTDF(writer io.Writer, reader io.ReadSeeker, opts ...TDFOption) (*TDFObject, error) { //nolint:funlen, gocognit, lll
 	inputSize, err := reader.Seek(0, io.SeekEnd)
 	if err != nil {
 		return nil, fmt.Errorf("readSeeker.Seek failed: %w", err)
@@ -101,7 +101,7 @@ func (sdk SDK) CreateTDF(writer io.Writer, reader io.ReadSeeker, opts ...TDFOpti
 		return nil, fmt.Errorf("NewTDFConfig failed: %w", err)
 	}
 
-	err = fillInPublicKeys(sdk.unwrapper, tdfConfig.kasInfoList)
+	err = fillInPublicKeys(s.unwrapper, tdfConfig.kasInfoList)
 	if err != nil {
 		return nil, err
 	}
@@ -360,7 +360,7 @@ func (t *TDFObject) createPolicyObject(attributes []string) (PolicyObject, error
 }
 
 // LoadTDF loads the tdf and prepare for reading the payload from TDF
-func (sdk SDK) LoadTDF(reader io.ReadSeeker) (*Reader, error) {
+func (s SDK) LoadTDF(reader io.ReadSeeker) (*Reader, error) {
 	// create tdf reader
 	tdfReader, err := archive.NewTDFReader(reader)
 	if err != nil {
@@ -381,7 +381,7 @@ func (sdk SDK) LoadTDF(reader io.ReadSeeker) (*Reader, error) {
 	return &Reader{
 		tdfReader: tdfReader,
 		manifest:  *manifestObj,
-		unwrapper: sdk.unwrapper,
+		unwrapper: s.unwrapper,
 	}, nil
 }