diff --git a/llvm/test/TableGen/lit.local.cfg b/llvm/test/TableGen/lit.local.cfg
index 0e827479cd412..9d6dfdc14bbfb 100644
--- a/llvm/test/TableGen/lit.local.cfg
+++ b/llvm/test/TableGen/lit.local.cfg
@@ -1,2 +1,10 @@
+import platform
+import lit.formats
+
 config.suffixes = [".td"]
 config.excludes = ["Common", "Inputs"]
+
+# AIX 'diff' command doesn't support --strip-trailing-cr, but the internal
+# python implementation does, so use that for cross platform compatibility
+if platform.system() == "AIX":
+    config.test_format = lit.formats.ShTest()
diff --git a/llvm/utils/lit/lit/llvm/config.py b/llvm/utils/lit/lit/llvm/config.py
index 1ef5796cd32e4..5f762ec7f3514 100644
--- a/llvm/utils/lit/lit/llvm/config.py
+++ b/llvm/utils/lit/lit/llvm/config.py
@@ -57,13 +57,6 @@ def __init__(self, lit_config, config):
                 self.lit_config.note("using lit tools: {}".format(path))
                 lit_path_displayed = True
 
-        if platform.system() == "AIX":
-            # Diff on AIX doesn't have all the required features (see
-            # https://github.com/llvm/llvm-project/pull/108871 and
-            # https://github.com/llvm/llvm-project/pull/112997#issuecomment-2429656192)
-            # so always use the internal shell.
-            self.use_lit_shell = True
-
         if platform.system() == "OS/390":
             self.with_environment("_BPXK_AUTOCVT", "ON")
             self.with_environment("_TAG_REDIR_IN", "TXT")