diff --git a/llvm/test/tools/llvm-exegesis/PowerPC/lit.local.cfg b/llvm/test/tools/llvm-exegesis/PowerPC/lit.local.cfg
index 135f5796b583..20de4ec2cc66 100644
--- a/llvm/test/tools/llvm-exegesis/PowerPC/lit.local.cfg
+++ b/llvm/test/tools/llvm-exegesis/PowerPC/lit.local.cfg
@@ -1,3 +1,7 @@
+if 's390x' in config.root.host_triple:
+    # These tests fail to run on s390x.
+    config.unsupported = True
+
 if not ('PowerPC' in config.root.targets):
     # We need support for PowerPC.
     config.unsupported = True
diff --git a/llvm/test/tools/llvm-exegesis/X86/lit.local.cfg b/llvm/test/tools/llvm-exegesis/X86/lit.local.cfg
index 7230f35fdb83..627bba4dc93d 100644
--- a/llvm/test/tools/llvm-exegesis/X86/lit.local.cfg
+++ b/llvm/test/tools/llvm-exegesis/X86/lit.local.cfg
@@ -1,3 +1,7 @@
+if 's390x' in config.root.host_triple:
+    # These tests fail to run on s390x.
+    config.unsupported = True
+
 if not ('X86' in config.root.targets):
     # We need support for X86.
     config.unsupported = True