diff --git a/testing/adios2/engine/dataman/CMakeLists.txt b/testing/adios2/engine/dataman/CMakeLists.txt
index 9503dc628c..5b5878069a 100644
--- a/testing/adios2/engine/dataman/CMakeLists.txt
+++ b/testing/adios2/engine/dataman/CMakeLists.txt
@@ -11,5 +11,6 @@ if(ADIOS2_HAVE_MPI)
   gtest_add_tests_helper(WriterSingleBuffer MPI_NOEXEC DataMan Engine.DataMan. "")
   gtest_add_tests_helper(ReaderDoubleBuffer MPI_NOEXEC DataMan Engine.DataMan. "")
   gtest_add_tests_helper(ReaderSingleBuffer MPI_NOEXEC DataMan Engine.DataMan. "")
-  gtest_add_tests_helper(Reliable MPI_NOEXEC DataMan Engine.DataMan. "")
+# Turning off DataMan.Reliable test as unstable - May 27, 2020
+#  gtest_add_tests_helper(Reliable MPI_NOEXEC DataMan Engine.DataMan. "")
 endif()