diff --git a/CMakeLists.txt b/CMakeLists.txt
index e12def34..d31de7cb 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -87,7 +87,6 @@ add_subdirectory(xo-facet)        # sep iface,data
 add_subdirectory(xo-allocutil)
 add_subdirectory(xo-refcnt)
 add_subdirectory(xo-subsys)
-#add_subdirectory(xo-randomgen)
 add_subdirectory(xo-flatstring)
 add_subdirectory(xo-pyutil)
 add_subdirectory(xo-reflect)
diff --git a/pkgs/xo-arena.nix b/pkgs/xo-arena.nix
index 6daab810..b216ba6c 100644
--- a/pkgs/xo-arena.nix
+++ b/pkgs/xo-arena.nix
@@ -4,7 +4,7 @@
 
   # xo dependencies
   xo-cmake,
-#  xo-refcnt,
+  xo-randomgen,
   xo-reflectutil,
   xo-indentlog,
 } :
@@ -15,13 +15,15 @@ stdenv.mkDerivation (finalattrs:
 
     src = ../xo-arena;
 
-    cmakeFlags = ["-DCMAKE_MODULE_PATH=${xo-cmake}/share/cmake"];
+    cmakeFlags = ["-DCMAKE_MODULE_PATH=${xo-cmake}/share/cmake"
+                  "-DENABLE_TESTING=1"
+                 ];
     doCheck = true;
     nativeBuildInputs = [
-      cmake catch2 xo-cmake
+      cmake catch2
+      xo-cmake xo-randomgen
     ];
     propagatedBuildInputs = [
-#      xo-refcnt
       xo-reflectutil
       xo-indentlog
     ];
diff --git a/xo-indentlog/utest/CMakeLists.txt b/xo-indentlog/utest/CMakeLists.txt
index 5fa2bf1b..b22b4eb8 100644
--- a/xo-indentlog/utest/CMakeLists.txt
+++ b/xo-indentlog/utest/CMakeLists.txt
@@ -6,12 +6,10 @@ set(SELF_SOURCE_FILES
     filename.test.cpp code_location.test.cpp function.test.cpp pretty_vector.test.cpp
     indentlog_utest_main.cpp log_streambuf.test.cpp toppstr.test.cpp cond.test.cpp)
 
-xo_add_utest_executable(${SELF_EXECUTABLE_NAME} ${SELF_SOURCE_FILES})
-
-# ----------------------------------------------------------------
-# 3rd party dependency: catch2
-
-xo_self_dependency(${SELF_EXECUTABLE_NAME} indentlog)
-xo_external_target_dependency(${SELF_EXECUTABLE_NAME} Catch2 Catch2::Catch2)
+if (ENABLE_TESTING)
+    xo_add_utest_executable(${SELF_EXECUTABLE_NAME} ${SELF_SOURCE_FILES})
+    xo_self_dependency(${SELF_EXECUTABLE_NAME} indentlog)
+    xo_external_target_dependency(${SELF_EXECUTABLE_NAME} Catch2 Catch2::Catch2)
+endif()
 
 # end CMakeLists.txt