diff --git a/deny.toml b/deny.toml
index 96463840..6a4ed2b5 100644
--- a/deny.toml
+++ b/deny.toml
@@ -95,6 +95,7 @@ allow = [
     "Apache-2.0 WITH LLVM-exception",
     "Unicode-3.0",
     "BSD-3-Clause",
+    "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