diff --git a/finagle-thriftmux/src/test/scala/BUILD b/finagle-thriftmux/src/test/scala/BUILD
index b84edf6d87..8cc182127d 100644
--- a/finagle-thriftmux/src/test/scala/BUILD
+++ b/finagle-thriftmux/src/test/scala/BUILD
@@ -2,7 +2,10 @@ junit_tests(
     sources = ["**/*.scala"],
     compiler_option_sets = ["fatal_warnings"],
     platform = "java8",
-    tags = ["bazel-compatible"],
+    tags = [
+        "bazel-compatible",
+        "known-to-fail-jira:CSL-12415",
+    ],
     dependencies = [
         "3rdparty/jvm/junit",
         "3rdparty/jvm/org/apache/thrift:libthrift",