diff --git a/influxdb2_client/src/api/buckets.rs b/influxdb2_client/src/api/buckets.rs
index 1e2b287ef5..37f812a610 100644
--- a/influxdb2_client/src/api/buckets.rs
+++ b/influxdb2_client/src/api/buckets.rs
@@ -16,6 +16,7 @@ impl Client {
 
         let response = self
             .request(Method::POST, &create_bucket_url)
+            .header("Content-Type", "application/json")
             .body(
                 serde_json::to_string(&post_bucket_request.unwrap_or_default())
                     .context(SerializingSnafu)?,
@@ -47,6 +48,7 @@ mod tests {
 
         let mock_server = mock("POST", "/api/v2/buckets")
             .match_header("Authorization", format!("Token {}", token).as_str())
+            .match_header("Content-Type", "application/json")
             .match_body(
                 format!(
                     r#"{{"orgID":"{}","name":"{}","retentionRules":[]}}"#,
diff --git a/influxdb2_client/src/api/label.rs b/influxdb2_client/src/api/label.rs
index fe59f68c49..bb98256caa 100644
--- a/influxdb2_client/src/api/label.rs
+++ b/influxdb2_client/src/api/label.rs
@@ -73,6 +73,7 @@ impl Client {
         };
         let response = self
             .request(Method::POST, &create_label_url)
+            .header("Content-Type", "application/json")
             .body(serde_json::to_string(&body).context(SerializingSnafu)?)
             .send()
             .await
@@ -100,6 +101,7 @@ impl Client {
         let body = LabelUpdate { name, properties };
         let response = self
             .request(Method::PATCH, &update_label_url)
+            .header("Content-Type", "application/json")
             .body(serde_json::to_string(&body).context(SerializingSnafu)?)
             .send()
             .await
@@ -198,6 +200,7 @@ mod tests {
 
         let mock_server = mock("POST", BASE_PATH)
             .match_header("Authorization", format!("Token {}", token).as_str())
+            .match_header("Content-Type", "application/json")
             .match_body(
                 format!(
                     r#"{{"orgID":"{}","name":"{}","properties":{{"some-key":"some-value"}}}}"#,
@@ -222,6 +225,7 @@ mod tests {
 
         let mock_server = mock("POST", BASE_PATH)
             .match_header("Authorization", format!("Token {}", token).as_str())
+            .match_header("Content-Type", "application/json")
             .match_body(format!(r#"{{"orgID":"{}","name":"{}"}}"#, org_id, name).as_str())
             .create();
 
@@ -242,6 +246,7 @@ mod tests {
 
         let mock_server = mock("PATCH", format!("{}/{}", BASE_PATH, label_id).as_str())
             .match_header("Authorization", format!("Token {}", token).as_str())
+            .match_header("Content-Type", "application/json")
             .match_body(
                 format!(
                     r#"{{"name":"{}","properties":{{"some-key":"some-value"}}}}"#,
@@ -267,6 +272,7 @@ mod tests {
 
         let mock_server = mock("PATCH", format!("{}/{}", BASE_PATH, label_id).as_str())
             .match_header("Authorization", format!("Token {}", token).as_str())
+            .match_header("Content-Type", "application/json")
             .match_body("{}")
             .create();
 
diff --git a/influxdb2_client/src/api/setup.rs b/influxdb2_client/src/api/setup.rs
index 4d4c3cc661..4b04cae280 100644
--- a/influxdb2_client/src/api/setup.rs
+++ b/influxdb2_client/src/api/setup.rs
@@ -54,6 +54,7 @@ impl Client {
 
         let response = self
             .request(Method::POST, &setup_init_url)
+            .header("Content-Type", "application/json")
             .body(serde_json::to_string(&body).context(SerializingSnafu)?)
             .send()
             .await
@@ -94,6 +95,7 @@ impl Client {
 
         let response = self
             .request(Method::POST, &setup_new_url)
+            .header("Content-Type", "application/json")
             .body(serde_json::to_string(&body).context(SerializingSnafu)?)
             .send()
             .await
@@ -138,6 +140,7 @@ mod tests {
         let retention_period_hrs = 1;
 
         let mock_server = mock("POST", "/api/v2/setup")
+            .match_header("Content-Type", "application/json")
             .match_body(
                 format!(
                     r#"{{"username":"{}","org":"{}","bucket":"{}","password":"{}","retentionPeriodHrs":{}}}"#,
@@ -173,6 +176,7 @@ mod tests {
 
         let mock_server = mock("POST", "/api/v2/setup/user")
             .match_header("Authorization", format!("Token {}", token).as_str())
+            .match_header("Content-Type", "application/json")
             .match_body(
                 format!(
                     r#"{{"username":"{}","org":"{}","bucket":"{}","password":"{}","retentionPeriodHrs":{}}}"#,
@@ -204,6 +208,7 @@ mod tests {
         let bucket = "some-bucket";
 
         let mock_server = mock("POST", "/api/v2/setup")
+            .match_header("Content-Type", "application/json")
             .match_body(
                 format!(
                     r#"{{"username":"{}","org":"{}","bucket":"{}"}}"#,
@@ -231,6 +236,7 @@ mod tests {
 
         let mock_server = mock("POST", "/api/v2/setup/user")
             .match_header("Authorization", format!("Token {}", token).as_str())
+            .match_header("Content-Type", "application/json")
             .match_body(
                 format!(
                     r#"{{"username":"{}","org":"{}","bucket":"{}"}}"#,