diff --git a/src/core/IronPython/Lib/iptest/test_env.py b/src/core/IronPython/Lib/iptest/test_env.py
index bbcd239b5..6e22556dc 100644
--- a/src/core/IronPython/Lib/iptest/test_env.py
+++ b/src/core/IronPython/Lib/iptest/test_env.py
@@ -4,6 +4,7 @@
 
 import os
 import sys
+import platform
 
 #------------------------------------------------------------------------------
 
@@ -15,6 +16,7 @@
 is_linux      =  sys.platform == 'linux'
 is_osx        =  sys.platform == 'darwin'
 is_posix      =  is_linux or is_osx
+is_arm64      =  platform.machine().lower() in ['aarch64', 'arm64']
 
 is_netcoreapp =  False
 is_netcoreapp21 = False
diff --git a/tests/suite/test_cliclass.py b/tests/suite/test_cliclass.py
index 0306a9205..5c081f382 100644
--- a/tests/suite/test_cliclass.py
+++ b/tests/suite/test_cliclass.py
@@ -4,7 +4,7 @@
 
 import sys
 import unittest
-from iptest import IronPythonTestCase, is_cli, is_debug, is_mono, is_net70, is_net80, is_netcoreapp, is_netcoreapp21, is_posix, big, run_test, skipUnlessIronPython
+from iptest import IronPythonTestCase, is_cli, is_debug, is_mono, is_net70, is_net80, is_netcoreapp, is_netcoreapp21, is_posix, is_arm64, big, run_test, skipUnlessIronPython
 
 if is_cli:
     import clr
@@ -1755,6 +1755,9 @@ def test_int_constructor_overflow(self):
         from iptest import clr_int_types, myint, myfloat
 
         val = 1 << 64
+        if is_mono and is_arm64:
+            # on Mono/ARM64, floating point rounding errors on ARM64 can cause 1 << 64 to fit in 64 bits
+            val += 10000
         for t in clr_int_types:
             self.assertRaises(OverflowError, t, val)
             self.assertRaises(OverflowError, t, str(val))
diff --git a/tests/suite/test_datetime_stdlib.py b/tests/suite/test_datetime_stdlib.py
index b8f11237a..d1d23a2dd 100644
--- a/tests/suite/test_datetime_stdlib.py
+++ b/tests/suite/test_datetime_stdlib.py
@@ -6,7 +6,7 @@
 ## Run selected tests from test_datetime from StdLib
 ##
 
-from iptest import is_ironpython, generate_suite, run_test
+from iptest import is_ironpython, is_mono, is_arm64, generate_suite, run_test
 
 import test.datetimetester
 
@@ -45,7 +45,13 @@ def load_tests(loader, standard_tests, pattern):
             test.datetimetester.TestTimeZone('test_constructor'),
         ]
 
-        return generate_suite(tests, failing_tests)
+        skip_tests = []
+        if is_mono and is_arm64:
+            skip_tests += [
+                test.datetimetester.TestTimeDelta('test_overflow'), # rounding differences
+            ]
+
+        return generate_suite(tests, failing_tests, skip_tests)
 
     else:
         return tests