diff --git a/.ns3.supp b/.ns3.supp
new file mode 100644
index 000000000..63af0bbeb
--- /dev/null
+++ b/.ns3.supp
@@ -0,0 +1,10 @@
+# This is the valgrind suppression file for ns-3.
+
+# libucs is included by openMPI. Added Feb 2024.
+# Errors generated by openucx 1.15.0-2
+{
+   ignore_libucs_init_memory_leak
+   Memcheck:Leak
+   ...
+   obj:*/libucs.so.*
+}
diff --git a/test.py b/test.py
index 16ab66880..4c4eab5cb 100755
--- a/test.py
+++ b/test.py
@@ -800,8 +800,8 @@ def make_paths():
 # no longer needed.  If it is needed again in the future, define the
 # below variable again, and remove the alternative definition to None
 #
-# VALGRIND_SUPPRESSIONS_FILE = "testpy.supp"
-VALGRIND_SUPPRESSIONS_FILE = None
+VALGRIND_SUPPRESSIONS_FILE = ".ns3.supp"
+# VALGRIND_SUPPRESSIONS_FILE = None
 
 
 def run_job_synchronously(shell_command, directory, valgrind, is_python, build_path=""):