diff --git a/licenses.txt b/licenses.txt
index 9a4dbc4e8ed592374571d25705f5025bbe6455ba..31312f367306b744bd82c2d5268113e8eb4048f4 100644
--- a/licenses.txt
+++ b/licenses.txt
@@ -12,5 +12,9 @@ MIT:
 - git https://github.com/nektro/zig-time
 - git https://github.com/nektro/zig-tracer
 
+Zlib:
+= https://spdx.org/licenses/Zlib
+- git https://github.com/madler/zlib
+
 Unspecified:
 - system_lib c