diff --git a/test/per_file_coverage.sh b/test/per_file_coverage.sh
index 486fa1362fdda..41b3491adeb0b 100755
--- a/test/per_file_coverage.sh
+++ b/test/per_file_coverage.sh
@@ -65,7 +65,7 @@ declare -a KNOWN_LOW_COVERAGE=(
 "source/extensions/wasm_runtime/wavm:0.0" # Noe enabled in coverage build
 "source/extensions/watchdog:85.7" # Death tests within extensions
 "source/extensions/watchdog/profile_action:85.7"
-"source/server:94.5" # flaky: be careful adjusting
+"source/server:94.4" # flaky: be careful adjusting. See https://github.com/envoyproxy/envoy/issues/15239
 "source/server/admin:95.1"
 "source/server/config_validation:75.6"
 )