diff --git a/CHANGELOG.md b/CHANGELOG.md
index c1245b4..6eea07c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,8 @@
 # Libcurl.js Changelog:
 
+## v0.6.4 (3/20/24):
+- Fix handling of request bodies
+
 ## v0.6.3 (3/20/24):
 - Fix an error during websocket cleanup
 
diff --git a/client/javascript/http.js b/client/javascript/http.js
index 110e650..56ae508 100644
--- a/client/javascript/http.js
+++ b/client/javascript/http.js
@@ -41,6 +41,7 @@ class HTTPSession extends CurlSession {
   request_async(url, params, body) {
     return new Promise((resolve, reject) => {
       let http_handle;
+      let body_ptr = null; 
   
       let headers_callback = (stream) => {
         let response_json = c_func_str(_http_get_info, [http_handle]);
@@ -53,6 +54,7 @@ class HTTPSession extends CurlSession {
         resolve(response);
       }
       let finish_callback = (error) => {
+        _free(body_ptr);
         if (error > 0) {
           error_msg(`Request "${url}" failed with error code ${error}: ${get_error_str(error)}`);
           reject(`Request failed with error code ${error}: ${get_error_str(error)}`);
@@ -65,12 +67,13 @@ class HTTPSession extends CurlSession {
         }
         this.remove_request(http_handle);
       }
-  
+      
+      body_ptr = body ? allocate_array(body) : null;
       let body_length = body ? body.length : 0;
       let params_json = JSON.stringify(params);
       
       http_handle = this.stream_response(url, headers_callback, finish_callback, params.signal);
-      c_func(_http_set_options, [http_handle, params_json, body, body_length]);
+      c_func(_http_set_options, [http_handle, params_json, body_ptr, body_length]);
       if (this.cookie_filename && params.credentials !== "omit") {
         c_func(_http_set_cookie_jar, [http_handle, this.cookie_filename]);
       }
@@ -139,8 +142,8 @@ class HTTPSession extends CurlSession {
     if (!params.headers["User-Agent"]) {
       params.headers["User-Agent"] = navigator.userAgent;
     }
-    if (body) {
-      params.headers["Content-Type"] = request_obj.headers.get("Content-Type");
+    if (body && !params.headers["Content-Type"]) {
+      params.headers["Content-Type"] = request_obj.headers.get("Content-Type") || "";
     }
 
     return body;
diff --git a/client/javascript/util.js b/client/javascript/util.js
index c71db82..ec47961 100644
--- a/client/javascript/util.js
+++ b/client/javascript/util.js
@@ -77,10 +77,15 @@ function data_to_array(data) {
 function c_func(target, args=[]) {
   let str_pointers = [];
   for (let i = 0; i < args.length; i++) {
-    if (typeof args[i] !== "string") {
-      continue;
+    let ptr = null;
+    if (typeof args[i] === "string") {
+      ptr = allocate_str(args[i]);
     }
-    let ptr = allocate_str(args[i]);
+    if (args[i] instanceof Uint8Array) {
+      ptr = allocate_array(args[i]);
+    }
+
+    if (!ptr) continue;
     args[i] = ptr;
     str_pointers.push(ptr);
   }
diff --git a/client/package.json b/client/package.json
index 8940462..b695331 100644
--- a/client/package.json
+++ b/client/package.json
@@ -1,6 +1,6 @@
 {
   "name": "libcurl.js",
-  "version": "0.6.3",
+  "version": "0.6.4",
   "description": "An experimental port of libcurl to WebAssembly for use in the browser.",
   "main": "libcurl.mjs",
   "exports": {
diff --git a/client/tests/run_tests.py b/client/tests/run_tests.py
index 2cff216..7ad511e 100644
--- a/client/tests/run_tests.py
+++ b/client/tests/run_tests.py
@@ -55,5 +55,8 @@ class JSTest(unittest.TestCase):
   def test_http_session(self):
     self.run_test("test_http_session.js")
 
+  def test_post(self):
+    self.run_test("test_post.js")
+
 if __name__ == "__main__":
   unittest.main()
\ No newline at end of file
diff --git a/client/tests/scripts/test_post.js b/client/tests/scripts/test_post.js
new file mode 100644
index 0000000..27172d0
--- /dev/null
+++ b/client/tests/scripts/test_post.js
@@ -0,0 +1,10 @@
+async function test() {
+  let payload = "hello".repeat(100);
+  let r = await libcurl.fetch("https://httpbin.org/anything", {
+    method: "POST",
+    body: new Blob([payload], {type: "text/plain"})
+  });
+  assert(r.status === 200, "wrong status");
+  let json = await r.json();
+  assert(json.data === payload, "server reports wrong payload");
+}
\ No newline at end of file