diff --git a/api/RuCaptcha.go b/api/RuCaptcha.go
index 005860c..5c9e44c 100644
--- a/api/RuCaptcha.go
+++ b/api/RuCaptcha.go
@@ -37,6 +37,24 @@ type ruCaptchaResponse interface{ text() string }
 func (a *ruCaptchaApi) wrap(handler func(url.Values) ruCaptchaResponse) func(http.ResponseWriter, *http.Request) {
 	return func(w http.ResponseWriter, r *http.Request) {
 		query := r.URL.Query()
+		if r.Method != "GET" {
+			switch strings.ToLower(r.Header.Get("Content-Type")) {
+			case "application/x-www-form-urlencoded":
+				r.ParseForm()
+			case "multipart/form-data":
+				r.ParseMultipartForm(0)
+			}
+		}
+
+		// merge form with url params
+		for key, values := range r.Form {
+			if _, ok := query[key]; ok {
+				query[key] = append(query[key], values...)
+			} else {
+				query[key] = values
+			}
+		}
+
 		useJson := false
 		if val := query.Get("json"); val != "" && val != "0" {
 			useJson = true