diff --git a/client/client.go b/client/client.go
index 1ee628d..36a458b 100644
--- a/client/client.go
+++ b/client/client.go
@@ -104,7 +104,7 @@ func checkResponseForErrors(resp *http.Response) error {
 }
 
 // Do an http request
-func (n *portainerClientImp) do(uri, method string, request io.Reader, requestType string, headers http.Header) (resp *http.Response, err error) {
+func (n *portainerClientImp) do(uri, method string, request io.Reader, headers http.Header) (resp *http.Response, err error) {
 	requestURL, err := n.url.Parse(uri)
 	if err != nil {
 		return
@@ -120,7 +120,6 @@ func (n *portainerClientImp) do(uri, method string, request io.Reader, requestTy
 	}
 
 	if request != nil {
-		req.Header.Set("Content-Type", requestType)
 		req.Header.Set("User-Agent", n.userAgent)
 	}
 
@@ -165,7 +164,9 @@ func (n *portainerClientImp) doJSON(uri, method string, headers http.Header, req
 		body = bytes.NewReader(reqBodyBytes)
 	}
 
-	resp, err := n.do(uri, method, body, "application/json", headers)
+	headers.Set("Content-Type", "application/json")
+
+	resp, err := n.do(uri, method, body, headers)
 	if err != nil {
 		return err
 	}
diff --git a/client/client_test.go b/client/client_test.go
index 7ed88d0..e22294f 100644
--- a/client/client_test.go
+++ b/client/client_test.go
@@ -85,11 +85,10 @@ func Test_portainerClientImp_do(t *testing.T) {
 		beforeFunctionCall func(t *testing.T, tt *fields)
 	}
 	type args struct {
-		uri         string
-		method      string
-		request     io.Reader
-		requestType string
-		headers     http.Header
+		uri     string
+		method  string
+		request io.Reader
+		headers http.Header
 	}
 	tests := []struct {
 		name          string
@@ -175,7 +174,7 @@ func Test_portainerClientImp_do(t *testing.T) {
 			if tt.fields.beforeFunctionCall != nil {
 				tt.fields.beforeFunctionCall(t, &tt.fields)
 			}
-			gotResp, err := n.do(tt.args.uri, tt.args.method, tt.args.request, tt.args.requestType, tt.args.headers)
+			gotResp, err := n.do(tt.args.uri, tt.args.method, tt.args.request, tt.args.headers)
 
 			assert.Equal(t, tt.wantErr, err != nil)
 			if tt.wantRespCheck != nil {