diff --git a/src/libstore-tests/derivation-parser-bench.cc b/src/libstore-tests/derivation-parser-bench.cc
index 1709eed1c..f0aa721cb 100644
--- a/src/libstore-tests/derivation-parser-bench.cc
+++ b/src/libstore-tests/derivation-parser-bench.cc
@@ -2,7 +2,7 @@
 #include "nix/store/derivations.hh"
 #include "nix/store/store-api.hh"
 #include "nix/util/experimental-features.hh"
-#include "nix/util/environment-variables.hh"
+#include "nix/util/tests/test-data.hh"
 #include "nix/store/store-open.hh"
 #include <fstream>
 #include <sstream>
@@ -50,11 +50,7 @@ static void BM_UnparseRealDerivationFile(benchmark::State & state, const std::st
 }
 
 // Register benchmarks for actual test derivation files if they exist
-BENCHMARK_CAPTURE(
-    BM_ParseRealDerivationFile, hello, getEnvNonEmpty("_NIX_TEST_UNIT_DATA").value() + "/derivation/hello.drv");
-BENCHMARK_CAPTURE(
-    BM_ParseRealDerivationFile, firefox, getEnvNonEmpty("_NIX_TEST_UNIT_DATA").value() + "/derivation/firefox.drv");
-BENCHMARK_CAPTURE(
-    BM_UnparseRealDerivationFile, hello, getEnvNonEmpty("_NIX_TEST_UNIT_DATA").value() + "/derivation/hello.drv");
-BENCHMARK_CAPTURE(
-    BM_UnparseRealDerivationFile, firefox, getEnvNonEmpty("_NIX_TEST_UNIT_DATA").value() + "/derivation/firefox.drv");
+BENCHMARK_CAPTURE(BM_ParseRealDerivationFile, hello, (getUnitTestData() / "derivation/hello.drv").string());
+BENCHMARK_CAPTURE(BM_ParseRealDerivationFile, firefox, (getUnitTestData() / "derivation/firefox.drv").string());
+BENCHMARK_CAPTURE(BM_UnparseRealDerivationFile, hello, (getUnitTestData() / "derivation/hello.drv").string());
+BENCHMARK_CAPTURE(BM_UnparseRealDerivationFile, firefox, (getUnitTestData() / "derivation/firefox.drv").string());
diff --git a/src/libstore-tests/nix_api_store.cc b/src/libstore-tests/nix_api_store.cc
index ea600f905..e67e5ffef 100644
--- a/src/libstore-tests/nix_api_store.cc
+++ b/src/libstore-tests/nix_api_store.cc
@@ -8,6 +8,7 @@
 #include "nix/store/tests/nix_api_store.hh"
 #include "nix/store/globals.hh"
 #include "nix/util/tests/string_callback.hh"
+#include "nix/util/tests/test-data.hh"
 #include "nix/util/url.hh"
 
 #include "store-tests-config.hh"
@@ -302,7 +303,7 @@ public:
 
         store = open_local_store();
 
-        std::filesystem::path unitTestData{getenv("_NIX_TEST_UNIT_DATA")};
+        std::filesystem::path unitTestData = nix::getUnitTestData();
         std::ifstream t{unitTestData / "derivation/ca/self-contained.json"};
         std::stringstream buffer;
         buffer << t.rdbuf();
@@ -357,7 +358,7 @@ TEST_F(nix_api_store_test_base, build_from_json)
 
     auto * store = open_local_store();
 
-    std::filesystem::path unitTestData{getenv("_NIX_TEST_UNIT_DATA")};
+    std::filesystem::path unitTestData = nix::getUnitTestData();
 
     std::ifstream t{unitTestData / "derivation/ca/self-contained.json"};
     std::stringstream buffer;
@@ -404,7 +405,7 @@ TEST_F(nix_api_store_test_base, nix_store_realise_invalid_system)
 
     auto * store = open_local_store();
 
-    std::filesystem::path unitTestData{getenv("_NIX_TEST_UNIT_DATA")};
+    std::filesystem::path unitTestData = nix::getUnitTestData();
     std::ifstream t{unitTestData / "derivation/ca/self-contained.json"};
     std::stringstream buffer;
     buffer << t.rdbuf();
@@ -449,7 +450,7 @@ TEST_F(nix_api_store_test_base, nix_store_realise_builder_fails)
 
     auto * store = open_local_store();
 
-    std::filesystem::path unitTestData{getenv("_NIX_TEST_UNIT_DATA")};
+    std::filesystem::path unitTestData = nix::getUnitTestData();
     std::ifstream t{unitTestData / "derivation/ca/self-contained.json"};
     std::stringstream buffer;
     buffer << t.rdbuf();
@@ -494,7 +495,7 @@ TEST_F(nix_api_store_test_base, nix_store_realise_builder_no_output)
 
     auto * store = open_local_store();
 
-    std::filesystem::path unitTestData{getenv("_NIX_TEST_UNIT_DATA")};
+    std::filesystem::path unitTestData = nix::getUnitTestData();
     std::ifstream t{unitTestData / "derivation/ca/self-contained.json"};
     std::stringstream buffer;
     buffer << t.rdbuf();
@@ -870,7 +871,7 @@ TEST_F(NixApiStoreTestWithRealisedPath, nix_store_get_fs_closure_error_propagati
  */
 static std::string load_json_from_test_data(const char * filename)
 {
-    std::filesystem::path unitTestData{getenv("_NIX_TEST_UNIT_DATA")};
+    std::filesystem::path unitTestData = nix::getUnitTestData();
     std::ifstream t{unitTestData / filename};
     std::stringstream buffer;
     buffer << t.rdbuf();
diff --git a/src/libutil-test-support/include/nix/util/tests/characterization.hh b/src/libutil-test-support/include/nix/util/tests/characterization.hh
index 67ad8fb51..52321828f 100644
--- a/src/libutil-test-support/include/nix/util/tests/characterization.hh
+++ b/src/libutil-test-support/include/nix/util/tests/characterization.hh
@@ -4,24 +4,11 @@
 #include <gtest/gtest.h>
 
 #include "nix/util/types.hh"
-#include "nix/util/environment-variables.hh"
 #include "nix/util/file-system.hh"
+#include "nix/util/tests/test-data.hh"
 
 namespace nix {
 
-/**
- * The path to the unit test data directory. See the contributing guide
- * in the manual for further details.
- */
-static inline std::filesystem::path getUnitTestData()
-{
-    auto data = getEnv("_NIX_TEST_UNIT_DATA");
-    if (!data)
-        throw Error(
-            "_NIX_TEST_UNIT_DATA environment variable is not set. Recommendation: use meson, example: 'meson test -C build --gdb'");
-    return std::filesystem::path(*data);
-}
-
 /**
  * Whether we should update "golden masters" instead of running tests
  * against them. See the contributing guide in the manual for further
diff --git a/src/libutil-test-support/include/nix/util/tests/meson.build b/src/libutil-test-support/include/nix/util/tests/meson.build
index 3be085892..9f09183f3 100644
--- a/src/libutil-test-support/include/nix/util/tests/meson.build
+++ b/src/libutil-test-support/include/nix/util/tests/meson.build
@@ -10,4 +10,5 @@ headers = files(
   'json-characterization.hh',
   'nix_api_util.hh',
   'string_callback.hh',
+  'test-data.hh',
 )
diff --git a/src/libutil-test-support/include/nix/util/tests/test-data.hh b/src/libutil-test-support/include/nix/util/tests/test-data.hh
new file mode 100644
index 000000000..6b965b848
--- /dev/null
+++ b/src/libutil-test-support/include/nix/util/tests/test-data.hh
@@ -0,0 +1,24 @@
+#pragma once
+///@file
+
+#include <filesystem>
+#include "nix/util/environment-variables.hh"
+#include "nix/util/error.hh"
+
+namespace nix {
+
+/**
+ * The path to the unit test data directory. See the contributing guide
+ * in the manual for further details.
+ */
+static inline std::filesystem::path getUnitTestData()
+{
+    auto data = getEnv("_NIX_TEST_UNIT_DATA");
+    if (!data)
+        throw Error(
+            "_NIX_TEST_UNIT_DATA environment variable is not set. "
+            "Recommendation: use meson, example: 'meson test -C build --gdb'");
+    return std::filesystem::path(*data);
+}
+
+} // namespace nix