diff --git a/deny.toml b/deny.toml
index ee5ae89b..2982ba3d 100644
--- a/deny.toml
+++ b/deny.toml
@@ -94,6 +94,7 @@ allow = [
     "CC0-1.0",
     "ISC",
     "OpenSSL",
+    "Zlib",
 ]
 # The confidence threshold for detecting a license from license text.
 # The higher the value, the more closely the license text must be to the