diff --git a/openmp/README.rst b/openmp/README.rst
--- a/openmp/README.rst
+++ b/openmp/README.rst
@@ -130,6 +130,10 @@
   Specify full path to ``FileCheck`` executable for running tests.  The default
   is to search the ``PATH`` and the directory in **OPENMP_LLVM_TOOLS_DIR**.
 
+**OPENMP_NOT_EXECUTABLE** = ``/path/to/not``
+  Specify full path to ``not`` executable for running tests.  The default
+  is to search the ``PATH`` and the directory in **OPENMP_LLVM_TOOLS_DIR**.
+
 Options for ``libomp``
 ----------------------
 
diff --git a/openmp/cmake/OpenMPTesting.cmake b/openmp/cmake/OpenMPTesting.cmake
--- a/openmp/cmake/OpenMPTesting.cmake
+++ b/openmp/cmake/OpenMPTesting.cmake
@@ -34,6 +34,17 @@
     set(ENABLE_CHECK_TARGETS FALSE PARENT_SCOPE)
     return()
   endif()
+
+  find_program(OPENMP_NOT_EXECUTABLE
+    NAMES not
+    PATHS ${OPENMP_LLVM_TOOLS_DIR})
+  if (NOT OPENMP_NOT_EXECUTABLE)
+    message(STATUS "Cannot find 'not'.")
+    message(STATUS "Please put 'not' in your PATH, set OPENMP_NOT_EXECUTABLE to its full path, or point OPENMP_LLVM_TOOLS_DIR to its directory.")
+    message(WARNING "The check targets will not be available!")
+    set(ENABLE_CHECK_TARGETS FALSE PARENT_SCOPE)
+    return()
+  endif()
 endfunction()
 
 if (${OPENMP_STANDALONE_BUILD})
@@ -55,6 +66,7 @@
   separate_arguments(OPENMP_LIT_ARGS)
 else()
   set(OPENMP_FILECHECK_EXECUTABLE ${LLVM_RUNTIME_OUTPUT_INTDIR}/FileCheck)
+  set(OPENMP_NOT_EXECUTABLE ${LLVM_RUNTIME_OUTPUT_INTDIR}/not)
 endif()
 
 # Macro to extract information about compiler from file. (no own scope)
diff --git a/openmp/libomptarget/deviceRTLs/nvptx/test/lit.cfg b/openmp/libomptarget/deviceRTLs/nvptx/test/lit.cfg
--- a/openmp/libomptarget/deviceRTLs/nvptx/test/lit.cfg
+++ b/openmp/libomptarget/deviceRTLs/nvptx/test/lit.cfg
@@ -67,3 +67,4 @@
 config.substitutions.append(("%flags", config.test_flags))
 
 config.substitutions.append(("%run", "%t"))
+config.substitutions.append((r"\bnot\b", config.libomptarget_not))
diff --git a/openmp/libomptarget/deviceRTLs/nvptx/test/lit.site.cfg.in b/openmp/libomptarget/deviceRTLs/nvptx/test/lit.site.cfg.in
--- a/openmp/libomptarget/deviceRTLs/nvptx/test/lit.site.cfg.in
+++ b/openmp/libomptarget/deviceRTLs/nvptx/test/lit.site.cfg.in
@@ -9,6 +9,7 @@
 config.omp_header_directory = "@LIBOMPTARGET_OPENMP_HEADER_FOLDER@"
 config.omp_host_rtl_directory = "@LIBOMPTARGET_OPENMP_HOST_RTL_FOLDER@"
 config.libomptarget_filecheck = "@OPENMP_FILECHECK_EXECUTABLE@"
+config.libomptarget_not = "@OPENMP_NOT_EXECUTABLE@"
 
 # Let the main config do the real work.
 lit_config.load_config(config, "@CMAKE_CURRENT_SOURCE_DIR@/lit.cfg")
diff --git a/openmp/libomptarget/test/lit.cfg b/openmp/libomptarget/test/lit.cfg
--- a/openmp/libomptarget/test/lit.cfg
+++ b/openmp/libomptarget/test/lit.cfg
@@ -101,6 +101,9 @@
         config.substitutions.append(("%libomptarget-run-" + \
             libomptarget_target, \
             "%t-" + libomptarget_target))
+        config.substitutions.append(("%libomptarget-run-fail-" + \
+            libomptarget_target, \
+            "not %t-" + libomptarget_target))
         config.substitutions.append(("%clangxx-" + libomptarget_target, \
             "%clangxx %openmp_flags %flags -fopenmp-targets=" + libomptarget_target))
         config.substitutions.append(("%clang-" + libomptarget_target, \
@@ -129,6 +132,9 @@
         config.substitutions.append(("%libomptarget-run-" + \
             libomptarget_target, \
             "echo ignored-command"))
+        config.substitutions.append(("%libomptarget-run-fail-" + \
+            libomptarget_target, \
+            "echo ignored-command"))
         config.substitutions.append(("%clang-" + libomptarget_target, \
             "echo ignored-command"))
         config.substitutions.append(("%clangxx-" + libomptarget_target, \
@@ -140,3 +146,4 @@
 config.substitutions.append(("%clang", config.test_c_compiler))
 config.substitutions.append(("%openmp_flags", config.test_openmp_flags))
 config.substitutions.append(("%flags", config.test_flags))
+config.substitutions.append((r"\bnot\b", config.libomptarget_not))
diff --git a/openmp/libomptarget/test/lit.site.cfg.in b/openmp/libomptarget/test/lit.site.cfg.in
--- a/openmp/libomptarget/test/lit.site.cfg.in
+++ b/openmp/libomptarget/test/lit.site.cfg.in
@@ -13,6 +13,7 @@
 config.libomptarget_all_targets = "@LIBOMPTARGET_ALL_TARGETS@".split()
 config.libomptarget_system_targets = "@LIBOMPTARGET_SYSTEM_TARGETS@".split()
 config.libomptarget_filecheck = "@OPENMP_FILECHECK_EXECUTABLE@"
+config.libomptarget_not = "@OPENMP_NOT_EXECUTABLE@"
 config.libomptarget_debug = @LIBOMPTARGET_DEBUG@
 
 # Let the main config do the real work.
diff --git a/openmp/runtime/test/lit.cfg b/openmp/runtime/test/lit.cfg
--- a/openmp/runtime/test/lit.cfg
+++ b/openmp/runtime/test/lit.cfg
@@ -127,6 +127,7 @@
 config.substitutions.append(("%openmp_flags", config.test_openmp_flags))
 config.substitutions.append(("%flags", config.test_flags))
 config.substitutions.append(("%python", '"%s"' % (sys.executable)))
+config.substitutions.append((r"\bnot\b", config.test_not))
 
 if config.has_ompt:
     config.substitutions.append(("FileCheck", "tee %%t.out | %s" % config.test_filecheck))
diff --git a/openmp/runtime/test/lit.site.cfg.in b/openmp/runtime/test/lit.site.cfg.in
--- a/openmp/runtime/test/lit.site.cfg.in
+++ b/openmp/runtime/test/lit.site.cfg.in
@@ -4,6 +4,7 @@
 config.test_cxx_compiler = "@OPENMP_TEST_CXX_COMPILER@"
 config.test_compiler_features = @OPENMP_TEST_COMPILER_FEATURES@
 config.test_filecheck = "@OPENMP_FILECHECK_EXECUTABLE@"
+config.test_not = "@OPENMP_NOT_EXECUTABLE@"
 config.test_openmp_flags = "@OPENMP_TEST_OPENMP_FLAGS@"
 config.test_extra_flags = "@OPENMP_TEST_FLAGS@"
 config.libomp_obj_root = "@CMAKE_CURRENT_BINARY_DIR@"
diff --git a/openmp/tools/archer/tests/lit.cfg b/openmp/tools/archer/tests/lit.cfg
--- a/openmp/tools/archer/tests/lit.cfg
+++ b/openmp/tools/archer/tests/lit.cfg
@@ -111,6 +111,7 @@
 config.substitutions.append(("%deflake", os.path.join(os.path.dirname(__file__), "deflake.bash")))
 
 config.substitutions.append(("FileCheck", config.test_filecheck))
+config.substitutions.append((r"\bnot\b", config.test_not))
 config.substitutions.append(("%sort-threads", "sort --numeric-sort --stable"))
 if config.operating_system == 'Windows':
     # No such environment variable on Windows.
diff --git a/openmp/tools/archer/tests/lit.site.cfg.in b/openmp/tools/archer/tests/lit.site.cfg.in
--- a/openmp/tools/archer/tests/lit.site.cfg.in
+++ b/openmp/tools/archer/tests/lit.site.cfg.in
@@ -4,6 +4,7 @@
 config.test_cxx_compiler = "@OPENMP_TEST_CXX_COMPILER@"
 config.test_compiler_features = @OPENMP_TEST_COMPILER_FEATURES@
 config.test_filecheck = "@OPENMP_FILECHECK_EXECUTABLE@"
+config.test_not = "@OPENMP_NOT_EXECUTABLE@"
 config.test_openmp_flags = "@OPENMP_TEST_OPENMP_FLAGS@"
 config.test_extra_flags = "@OPENMP_TEST_FLAGS@"
 config.libomp_obj_root = "@CMAKE_CURRENT_BINARY_DIR@"