diff --git a/CMakeLists.txt b/CMakeLists.txt
index c4f5ee0097d..9e71962bc77 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -256,6 +256,9 @@ if(GINKGO_BUILD_BENCHMARKS)
     find_package(gflags 2.2.2 QUIET)
     find_package(nlohmann_json 3.9.1 QUIET)
 endif()
+if(GINKGO_BUILD_CONFIG_PARSER)
+    find_package(nlohmann_json 3.9.1 QUIET)
+endif()
 
 # System provided, third party libraries (not bundled!)
 set(GINKGO_HAVE_HWLOC 0)
diff --git a/extension/property_tree/include/property_tree/json_parser.hpp b/extension/property_tree/include/property_tree/json_parser.hpp
index bc8460ff8df..da2083ba794 100644
--- a/extension/property_tree/include/property_tree/json_parser.hpp
+++ b/extension/property_tree/include/property_tree/json_parser.hpp
@@ -40,8 +40,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #include <type_traits>
 
 
-#include <rapidjson/document.h>
-#include <rapidjson/istreamwrapper.h>
+#include <nlohmann/json.hpp>
 
 
 #include <ginkgo/core/config/property_tree.hpp>
@@ -51,29 +50,31 @@ namespace gko {
 namespace extension {
 
 
-void json_parser(gko::config::pnode& ptree, rapidjson::Value& dom)
+inline void json_parser(gko::config::pnode& ptree, const nlohmann::json& dom)
 {
-    if (dom.IsArray()) {
-        auto array = dom.GetArray();
-        int num = array.Size();
+    if (dom.is_array()) {
+        int num = dom.size();
         ptree.get_array().resize(num);
         for (int i = 0; i < num; i++) {
-            json_parser(ptree.at(i), array[i]);
+            json_parser(ptree.at(i), dom[i]);
         }
-    } else if (dom.IsObject()) {
+    } else if (dom.is_object()) {
         auto& list = ptree.get_map();
-        for (auto& m : dom.GetObject()) {
-            json_parser(list[m.name.GetString()], dom[m.name.GetString()]);
+        for (auto& m : dom.items()) {
+            json_parser(list[m.key()], m.value());
         }
     } else {
-        if (dom.IsInt64()) {
-            ptree = gko::config::pnode{dom.GetInt64()};
-        } else if (dom.IsBool()) {
-            ptree = gko::config::pnode{dom.GetBool()};
-        } else if (dom.IsDouble()) {
-            ptree = gko::config::pnode{dom.GetDouble()};
+        if (dom.is_number_integer()) {
+            ptree = gko::config::pnode{dom.template get<long long int>()};
+        } else if (dom.is_boolean()) {
+            ptree = gko::config::pnode{dom.template get<bool>()};
+        } else if (dom.is_number_float()) {
+            ptree = gko::config::pnode{dom.template get<double>()};
+        } else if (dom.is_string()) {
+            ptree = gko::config::pnode{
+                std::string(dom.template get<std::string>())};
         } else {
-            ptree = gko::config::pnode{std::string(dom.GetString())};
+            ptree = gko::config::pnode{};
         }
     }
 }
diff --git a/extension/property_tree/test/CMakeLists.txt b/extension/property_tree/test/CMakeLists.txt
index 5b4b4fb0014..b461ca8dc1d 100644
--- a/extension/property_tree/test/CMakeLists.txt
+++ b/extension/property_tree/test/CMakeLists.txt
@@ -24,4 +24,4 @@ function(gkoext_pt_create_test test_name)
 endfunction(gkoext_pt_create_test)
 
 
-gkoext_pt_create_test(json_parser rapidjson ginkgo)
\ No newline at end of file
+gkoext_pt_create_test(json_parser nlohmann_json::nlohmann_json ginkgo)
\ No newline at end of file
diff --git a/extension/property_tree/test/json_parser.cpp b/extension/property_tree/test/json_parser.cpp
index 9a7d9cc8511..49b05085e11 100644
--- a/extension/property_tree/test/json_parser.cpp
+++ b/extension/property_tree/test/json_parser.cpp
@@ -34,7 +34,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 
 #include <gtest/gtest.h>
-#include <rapidjson/document.h>
+#include <nlohmann/json.hpp>
 
 
 #include <ginkgo/core/config/property_tree.hpp>
@@ -50,9 +50,7 @@ using namespace gko::extension;
 TEST(JsonParser, ReadObject)
 {
     const char json[] = R"({"base": "ReferenceExecutor"})";
-    rapidjson::StringStream s(json);
-    rapidjson::Document d;
-    d.ParseStream(s);
+    auto d = nlohmann::json::parse(json);
     gko::config::pnode ptree;
 
     json_parser(ptree, d);
@@ -65,21 +63,20 @@ TEST(JsonParser, ReadInput2)
 {
     const char json[] =
         R"({"base": "Csr",
-            "dim": [3, 4], 
+            "dim": [3, 4.5], 
             "exec": {"base": "ReferenceExecutor"}})";
     std::istringstream iss(R"({
   base: "Csr"
   dim: [
     3
-    4
+    4.5
   ]
   exec: {
     base: "ReferenceExecutor"
   }
-})");
-    rapidjson::StringStream s(json);
-    rapidjson::Document d;
-    d.ParseStream(s);
+}
+)");
+    auto d = nlohmann::json::parse(json);
     gko::config::pnode ptree;
 
     json_parser(ptree, d);
@@ -100,10 +97,9 @@ TEST(JsonParser, ReadInput3)
   {
     name: "B"
   }
-])");
-    rapidjson::StringStream s(json);
-    rapidjson::Document d;
-    d.ParseStream(s);
+]
+)");
+    auto d = nlohmann::json::parse(json);
     gko::config::pnode ptree;
 
     json_parser(ptree, d);
diff --git a/third_party/CMakeLists.txt b/third_party/CMakeLists.txt
index 749d24b87bd..08f10c95362 100644
--- a/third_party/CMakeLists.txt
+++ b/third_party/CMakeLists.txt
@@ -16,6 +16,12 @@ if(GINKGO_BUILD_BENCHMARKS)
     endif()
 endif()
 
+if(GINKGO_BUILD_CONFIG_PARSER)
+    if (NOT nlohmann_json_FOUND)
+        add_subdirectory(nlohmann_json)
+    endif()
+endif()
+
 if (GINKGO_TEST_NONDEFAULT_STREAM)
     add_subdirectory(identify_stream_usage)
 endif()
diff --git a/third_party/nlohmann_json/CMakeLists.txt b/third_party/nlohmann_json/CMakeLists.txt
index 6f413e458b9..b76d5d8b0b8 100644
--- a/third_party/nlohmann_json/CMakeLists.txt
+++ b/third_party/nlohmann_json/CMakeLists.txt
@@ -6,5 +6,6 @@ FetchContent_Declare(
     GIT_TAG        v3.9.1
 )
 set(JSON_BuildTests OFF CACHE INTERNAL "")
-set(JSON_Install OFF CACHE INTERNAL "")
+set(JSON_Install ON CACHE INTERNAL "")
+# default cmake installation is in CMAKE_INSTALL_PREFIX/share/cmake
 FetchContent_MakeAvailable(nlohmann_json)