diff --git a/src/ecmascript/mujs/xhr.cpp b/src/ecmascript/mujs/xhr.cpp
index c26fcb6e..315a903e 100644
--- a/src/ecmascript/mujs/xhr.cpp
+++ b/src/ecmascript/mujs/xhr.cpp
@@ -830,7 +830,7 @@ mjs_xhr_send(js_State *J)
 
 	const char *body = NULL;
 
-	if (xhr->method == POST && !js_isundefined(J, 1)) {
+	if (xhr->async && xhr->method == POST && !js_isundefined(J, 1)) {
 		body = js_tostring(J, 1);
 
 		if (body) {
@@ -881,6 +881,17 @@ mjs_xhr_send(js_State *J)
 			curl_easy_setopt(curl_handle, CURLOPT_NOPROGRESS, 1L);
 			curl_easy_setopt(curl_handle, CURLOPT_WRITEFUNCTION, write_data);
 			curl_easy_setopt(curl_handle, CURLOPT_WRITEDATA, xhr);
+
+			if (!js_isundefined(J, 1)) {
+				const char *body = js_tostring(J, 1);
+				size_t size = strlen(body);
+
+				if (body) {
+					curl_easy_setopt(curl_handle, CURLOPT_POSTFIELDSIZE, (long) size);
+					curl_easy_setopt(curl_handle, CURLOPT_COPYPOSTFIELDS, body);
+				}
+			}
+
 			curl_easy_perform(curl_handle);
 			curl_easy_cleanup(curl_handle);
 			xhr->readyState = DONE;
diff --git a/src/ecmascript/quickjs/xhr.cpp b/src/ecmascript/quickjs/xhr.cpp
index c22e17ea..5b9ddef0 100644
--- a/src/ecmascript/quickjs/xhr.cpp
+++ b/src/ecmascript/quickjs/xhr.cpp
@@ -1352,7 +1352,7 @@ xhr_send(JSContext *ctx, JSValueConst this_val, int argc, JSValueConst *argv)
 	if (!x->sent) {
 		JSValue arg = argv[0];
 
-		if (x->method == POST && JS_IsString(arg)) {
+		if (x->async && x->method == POST && JS_IsString(arg)) {
 			size_t size;
 			const char *body = JS_ToCStringLen(ctx, &size, arg);
 
@@ -1413,6 +1413,20 @@ xhr_send(JSContext *ctx, JSValueConst this_val, int argc, JSValueConst *argv)
 				curl_easy_setopt(curl_handle, CURLOPT_WRITEFUNCTION, write_data);
 				/* write the page body to this file handle */
 				curl_easy_setopt(curl_handle, CURLOPT_WRITEDATA, x);
+
+				JSValue arg = argv[0];
+				if (JS_IsString(arg)) {
+					size_t size;
+					const char *body = JS_ToCStringLen(ctx, &size, arg);
+
+					if (body) {
+						curl_easy_setopt(curl_handle, CURLOPT_POSTFIELDSIZE, (long) size);
+						curl_easy_setopt(curl_handle, CURLOPT_COPYPOSTFIELDS, body);
+
+						JS_FreeCString(ctx, body);
+					}
+				}
+
 				/* get it! */
 				curl_easy_perform(curl_handle);
 				/* cleanup curl stuff */
diff --git a/src/ecmascript/spidermonkey/xhr.cpp b/src/ecmascript/spidermonkey/xhr.cpp
index 1f13850d..b1a00131 100644
--- a/src/ecmascript/spidermonkey/xhr.cpp
+++ b/src/ecmascript/spidermonkey/xhr.cpp
@@ -988,7 +988,7 @@ xhr_send(JSContext *ctx, unsigned int argc, JS::Value *rval)
 
 	char *body = NULL;
 
-	if (xhr->method == POST && argc == 1) {
+	if (xhr->async && xhr->method == POST && argc == 1) {
 		body = jsval_to_string(ctx, args[0]);
 
 		if (body) {
@@ -1041,6 +1041,19 @@ xhr_send(JSContext *ctx, unsigned int argc, JS::Value *rval)
 			curl_easy_setopt(curl_handle, CURLOPT_NOPROGRESS, 1L);
 			curl_easy_setopt(curl_handle, CURLOPT_WRITEFUNCTION, write_data);
 			curl_easy_setopt(curl_handle, CURLOPT_WRITEDATA, xhr);
+
+			if (argc > 0) {
+				char *body = jsval_to_string(ctx, args[0]);
+
+				if (body) {
+					size_t size = strlen(body);
+
+					curl_easy_setopt(curl_handle, CURLOPT_POSTFIELDSIZE, (long) size);
+					curl_easy_setopt(curl_handle, CURLOPT_COPYPOSTFIELDS, body);
+
+					mem_free(body);
+				}
+			}
 			curl_easy_perform(curl_handle);
 			curl_easy_cleanup(curl_handle);
 			xhr->readyState = DONE;