diff --git a/modules/openapi-generator/src/main/resources/go/client.mustache b/modules/openapi-generator/src/main/resources/go/client.mustache
index f1270b3c692d8..655bdc0938146 100644
--- a/modules/openapi-generator/src/main/resources/go/client.mustache
+++ b/modules/openapi-generator/src/main/resources/go/client.mustache
@@ -4,6 +4,7 @@ package {{packageName}}
 import (
 	"bytes"
 	"context"
+	"encoding"
 	"encoding/json"
 	"encoding/xml"
 	"errors"
@@ -175,6 +176,14 @@ func parameterAddToHeaderOrQuery(headerOrQueryParams interface{}, keyPrefix stri
 					parameterAddToHeaderOrQuery(headerOrQueryParams, keyPrefix, t.Format(time.RFC3339), collectionType)
 					return
 				}
+				if t, ok := obj.(encoding.TextMarshaler); ok {
+					data,err := t.MarshalText()
+					if err != nil {
+						return
+					}
+					parameterAddToHeaderOrQuery(headerOrQueryParams, keyPrefix, string(data), collectionType)
+					return
+				}
 				value = v.Type().String() + " value"
 			case reflect.Slice:
 				var indValue = reflect.ValueOf(obj)
@@ -312,7 +321,7 @@ func (c *APIClient) prepareRequest(
 	// add form parameters and file if available.
 	if strings.HasPrefix(headerParams["Content-Type"], "multipart/form-data") && len(formParams) > 0 || (len(formFiles) > 0) {
 		if body != nil {
-			return nil, errors.New("Cannot specify postBody and multipart form at the same time.")
+			return nil, errors.New("cannot specify postBody and multipart form at the same time")
 		}
 		body = &bytes.Buffer{}
 		w := multipart.NewWriter(body)
@@ -353,7 +362,7 @@ func (c *APIClient) prepareRequest(
 
 	if strings.HasPrefix(headerParams["Content-Type"], "application/x-www-form-urlencoded") && len(formParams) > 0 {
 		if body != nil {
-			return nil, errors.New("Cannot specify postBody and x-www-form-urlencoded form at the same time.")
+			return nil, errors.New("cannot specify postBody and x-www-form-urlencoded form at the same time")
 		}
 		body = &bytes.Buffer{}
 		body.WriteString(formParams.Encode())
@@ -518,7 +527,8 @@ func (c *APIClient) decode(v interface{}, b []byte, contentType string) (err err
 		*s = string(b)
 		return nil
 	}
-	if f, ok := v.(*os.File); ok {
+	if _, ok := v.(*os.File); ok {
+		var f *os.File
 		f, err = os.CreateTemp("", "HttpClientFile")
 		if err != nil {
 			return
@@ -530,7 +540,8 @@ func (c *APIClient) decode(v interface{}, b []byte, contentType string) (err err
 		_, err = f.Seek(0, io.SeekStart)
 		return
 	}
-	if f, ok := v.(**os.File); ok {
+	if _, ok := v.(**os.File); ok {
+		var f **os.File
 		*f, err = os.CreateTemp("", "HttpClientFile")
 		if err != nil {
 			return
@@ -555,7 +566,7 @@ func (c *APIClient) decode(v interface{}, b []byte, contentType string) (err err
 					return err
 				}
 			} else {
-				return errors.New("Unknown type with GetActualInstance but no unmarshalObj.UnmarshalJSON defined")
+				return errors.New("unknown type with GetActualInstance but no unmarshalObj.UnmarshalJSON defined")
 			}
 		} else if err = json.Unmarshal(b, v); err != nil { // simple model
 			return err
@@ -628,7 +639,7 @@ func setBody(body interface{}, contentType string) (bodyBuf *bytes.Buffer, err e
 	}
 
 	if bodyBuf.Len() == 0 {
-		err = fmt.Errorf("invalid body type %s\n", contentType)
+		err = fmt.Errorf("invalid body type %s", contentType)
 		return nil, err
 	}
 	return bodyBuf, nil