diff --git a/cmake/ci.cmake b/cmake/ci.cmake
index 9a8136165f..f7ac099fdd 100644
--- a/cmake/ci.cmake
+++ b/cmake/ci.cmake
@@ -683,7 +683,7 @@ add_custom_target(ci_infer
 
 add_custom_target(ci_offline_testdata
     COMMAND mkdir -p ${PROJECT_BINARY_DIR}/build_offline_testdata/test_data
-    COMMAND cd ${PROJECT_BINARY_DIR}/build_offline_testdata/test_data && ${GIT_TOOL} clone -c advice.detachedHead=false --branch v3.0.0 https://github.com/nlohmann/json_test_data.git --quiet --depth 1
+    COMMAND cd ${PROJECT_BINARY_DIR}/build_offline_testdata/test_data && ${GIT_TOOL} clone -c advice.detachedHead=false --branch v3.1.0 https://github.com/nlohmann/json_test_data.git --quiet --depth 1
     COMMAND ${CMAKE_COMMAND}
         -DCMAKE_BUILD_TYPE=Debug -GNinja
         -DJSON_BuildTests=ON -DJSON_FastTests=ON -DJSON_TestDataDirectory=${PROJECT_BINARY_DIR}/build_offline_testdata/test_data/json_test_data
diff --git a/cmake/download_test_data.cmake b/cmake/download_test_data.cmake
index f516a7c3b2..1bb998dae6 100644
--- a/cmake/download_test_data.cmake
+++ b/cmake/download_test_data.cmake
@@ -1,5 +1,5 @@
 set(JSON_TEST_DATA_URL     https://github.com/nlohmann/json_test_data)
-set(JSON_TEST_DATA_VERSION 3.0.0)
+set(JSON_TEST_DATA_VERSION 3.1.0)
 
 # if variable is set, use test data from given directory rather than downloading them
 if(JSON_TestDataDirectory)
diff --git a/test/src/unit-bjdata.cpp b/test/src/unit-bjdata.cpp
index bdf390f298..bc6c52833a 100644
--- a/test/src/unit-bjdata.cpp
+++ b/test/src/unit-bjdata.cpp
@@ -3237,7 +3237,6 @@ TEST_CASE("all BJData first bytes")
 }
 #endif
 
-#if defined(BJDATA_TEST_ROUNDTRIP)
 TEST_CASE("BJData roundtrips" * doctest::skip())
 {
     SECTION("input from self-generated BJData files")
@@ -3354,4 +3353,3 @@ TEST_CASE("BJData roundtrips" * doctest::skip())
         }
     }
 }
-#endif