diff --git a/http_headers_fuzzer/requirements.txt b/http_headers_fuzzer/requirements.txt
index 566083c..29548fb 100644
--- a/http_headers_fuzzer/requirements.txt
+++ b/http_headers_fuzzer/requirements.txt
@@ -1 +1,2 @@
 requests==2.22.0
+idna>=3.7 # not directly required, pinned by Snyk to avoid a vulnerability