diff --git a/client.cpp b/client.cpp
index 2922e60..2f395ec 100644
--- a/client.cpp
+++ b/client.cpp
@@ -278,7 +278,8 @@ nlohmann::json MastodonClient::_send_request(std::optional<std::string> cache_ke
     long response_code = this->_response_status_code();
     nlohmann::json j = nlohmann::json::parse(res);
     if (response_code != 200) {
-        throw MastodonException(response_code, j.at("error").get<std::string>());
+        const nlohmann::json& error = j.at("error");
+        throw MastodonException(response_code, error.is_string() ? error.get<std::string>() : error.dump());
     }
 
     if (redis && cache_key) {