diff --git a/src/http/client.rs b/src/http/client.rs
index 734449765c3..5b8e8975749 100644
--- a/src/http/client.rs
+++ b/src/http/client.rs
@@ -101,7 +101,7 @@ pub struct EspHttpConnection {
     follow_redirects_policy: FollowRedirectsPolicy,
     event_handler: Box<Option<Box<dyn Fn(&esp_http_client_event_t) -> esp_err_t>>>,
     state: State,
-    request_content_len: u64,
+    request_content_len: i64,
     follow_redirects: bool,
     headers: BTreeMap<Uncased<'static>, String>,
     content_len_header: UnsafeCell<Option<Option<String>>>,
@@ -246,7 +246,7 @@ impl EspHttpConnection {
             _ => false,
         };
 
-        self.request_content_len = content_len.unwrap_or(0);
+        self.request_content_len = content_len.unwrap_or(-1);
 
         esp!(unsafe { esp_http_client_open(self.raw_client, self.request_content_len as _) })?;