diff --git a/pyproject.toml b/pyproject.toml
index a10ef11..41e9d9c 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -7,7 +7,7 @@ requires-python = ">=3.12"
 dependencies = [
     "click>=8.1.8",
     "nanopub>=2.2.2",
-    "python-ulid>=3.1.0",
+    "python-ulid==3.1.0",
 ]
 
 [dependency-groups]