diff --git a/deny.toml b/deny.toml
index 288725c8..fdd87e4b 100644
--- a/deny.toml
+++ b/deny.toml
@@ -94,6 +94,7 @@ allow = [
     "MIT",
     "Apache-2.0",
     "Unicode-3.0",
+    "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