diff --git a/untests/CMakeLists.txt b/untests/CMakeLists.txt
index 31c8cc6..1ecfbf7 100644
--- a/untests/CMakeLists.txt
+++ b/untests/CMakeLists.txt
@@ -5,38 +5,6 @@ project(curly.hpp.untests)
 
 include(FetchContent)
 
-#
-# nlohmann/json
-#
-
-set(JSON_BuildTests OFF CACHE BOOL "" FORCE)
-
-FetchContent_Declare(
-    nlohmann_json
-    GIT_REPOSITORY https://github.com/nlohmann/json)
-
-FetchContent_GetProperties(nlohmann_json)
-if(NOT nlohmann_json_POPULATED)
-    FetchContent_Populate(nlohmann_json)
-    add_subdirectory(${nlohmann_json_SOURCE_DIR} ${nlohmann_json_BINARY_DIR})
-endif()
-
-#
-# catchorg/catch2
-#
-
-set(CATCH_BUILD_TESTING OFF CACHE BOOL "" FORCE)
-
-FetchContent_Declare(
-    catchorg_catch2
-    GIT_REPOSITORY https://github.com/catchorg/catch2)
-
-FetchContent_GetProperties(catchorg_catch2)
-if(NOT catchorg_catch2_POPULATED)
-    FetchContent_Populate(catchorg_catch2)
-    add_subdirectory(${catchorg_catch2_SOURCE_DIR} ${catchorg_catch2_BINARY_DIR})
-endif()
-
 #
 # coverage
 #
@@ -55,9 +23,7 @@ endif()
 
 file(GLOB UNTESTS_SOURCES "*.cpp" "*.hpp")
 add_executable(${PROJECT_NAME} ${UNTESTS_SOURCES})
-
-target_link_libraries(${PROJECT_NAME}
-    nlohmann_json Catch2 curly.hpp)
+target_link_libraries(${PROJECT_NAME} curly.hpp)
 
 target_compile_options(${PROJECT_NAME}
     PRIVATE
@@ -68,3 +34,33 @@ target_compile_options(${PROJECT_NAME}
         -Wall -Wextra -Wpedantic>)
 
 add_test(${PROJECT_NAME} ${PROJECT_NAME})
+
+#
+# catchorg/catch2
+#
+
+FetchContent_Declare(
+    catchorg_catch2
+    GIT_REPOSITORY https://github.com/catchorg/catch2)
+
+FetchContent_GetProperties(catchorg_catch2)
+if(NOT catchorg_catch2_POPULATED)
+    FetchContent_Populate(catchorg_catch2)
+    target_include_directories(${PROJECT_NAME}
+        PRIVATE ${catchorg_catch2_SOURCE_DIR}/single_include)
+endif()
+
+#
+# tencent/rapidjson
+#
+
+FetchContent_Declare(
+    tencent_rapidjson
+    GIT_REPOSITORY https://github.com/tencent/rapidjson)
+
+FetchContent_GetProperties(tencent_rapidjson)
+if(NOT tencent_rapidjson_POPULATED)
+    FetchContent_Populate(tencent_rapidjson)
+    target_include_directories(${PROJECT_NAME}
+        PRIVATE ${tencent_rapidjson_SOURCE_DIR}/include)
+endif()
diff --git a/untests/curly_tests.cpp b/untests/curly_tests.cpp
index 08e76e9..9c4458b 100644
--- a/untests/curly_tests.cpp
+++ b/untests/curly_tests.cpp
@@ -10,8 +10,8 @@
 #include <fstream>
 #include <iostream>
 
-#include <nlohmann/json.hpp>
-using json = nlohmann::json;
+#include <rapidjson/document.h>
+namespace json = rapidjson;
 
 #include <curly.hpp/curly.hpp>
 namespace net = curly_hpp;
@@ -21,6 +21,14 @@ namespace net = curly_hpp;
 
 namespace
 {
+    json::Document json_parse(std::string_view data) {
+        json::Document d;
+        if ( d.Parse(data.data(), data.size()).HasParseError() ) {
+            throw std::logic_error("untests: failed to parse json");
+        }
+        return d;
+    }
+
     class verbose_uploader : public net::upload_handler {
     public:
         verbose_uploader() = default;
@@ -223,7 +231,7 @@ TEST_CASE("curly") {
             .header("Custom-Header-2", "custom header value 2")
             .send();
         const auto resp = req.get();
-        const auto content_j = json::parse(resp.content().as_string_view());
+        const auto content_j = json_parse(resp.content().as_string_view());
         REQUIRE(content_j["headers"]["Custom-Header-1"] == "custom_header_value_1");
         REQUIRE(content_j["headers"]["Custom-Header-2"] == "custom header value 2");
     }
@@ -235,7 +243,7 @@ TEST_CASE("curly") {
                 .method(net::methods::get)
                 .send();
             const auto resp = req.get();
-            const auto content_j = json::parse(resp.content().as_string_view());
+            const auto content_j = json_parse(resp.content().as_string_view());
             REQUIRE(content_j["hello"] == "world");
             REQUIRE(content_j["world"] == "hello");
         }
@@ -245,7 +253,7 @@ TEST_CASE("curly") {
                 .method(net::methods::post)
                 .send();
             const auto resp = req.get();
-            const auto content_j = json::parse(resp.content().as_string_view());
+            const auto content_j = json_parse(resp.content().as_string_view());
             REQUIRE(content_j["hello"] == "world");
             REQUIRE(content_j["world"] == "hello");
         }
@@ -335,7 +343,7 @@ TEST_CASE("curly") {
                 .header("Content-Type", "application/json")
                 .content(R"({"hello":"world"})")
                 .send().get();
-            const auto content_j = json::parse(resp.content().as_string_view());
+            const auto content_j = json_parse(resp.content().as_string_view());
             REQUIRE(content_j["data"] == R"({"hello":"world"})");
         }
         {
@@ -345,7 +353,7 @@ TEST_CASE("curly") {
                 .header("Content-Type", "application/json")
                 .content(R"({"hello":"world"})")
                 .send().get();
-            const auto content_j = json::parse(resp.content().as_string_view());
+            const auto content_j = json_parse(resp.content().as_string_view());
             REQUIRE(content_j["data"] == R"({"hello":"world"})");
         }
         {
@@ -355,7 +363,7 @@ TEST_CASE("curly") {
                 .header("Content-Type", "application/x-www-form-urlencoded")
                 .content("hello=world&world=hello")
                 .send().get();
-            const auto content_j = json::parse(resp.content().as_string_view());
+            const auto content_j = json_parse(resp.content().as_string_view());
             REQUIRE(content_j["form"]["hello"] == "world");
             REQUIRE(content_j["form"]["world"] == "hello");
         }