diff --git a/pyproject.toml b/pyproject.toml
index 70cb6c9a..b692a0bf 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -41,8 +41,6 @@ dependencies = [
     # Support for vcfpy
     "pysam >=0.22.1,<1",
     "pytabix >=0.1,<1",
-    # pytabix requires zlib, but does not list it as a dependency
-    "zlib >=1.3.1,<2",
     # Jinja 2 template rendering
     "jinja2 >=3.1.4,<4",
     # Parsing of ISA-tab.