diff --git a/python/pyproject.toml b/python/pyproject.toml
index cd069ac..032efd6 100644
--- a/python/pyproject.toml
+++ b/python/pyproject.toml
@@ -12,7 +12,7 @@ requires-python = ">=3.11"
 dependencies = [
   # format-nongpl registers date-time/uri/duration/hostname checkers used as assertions
   "jsonschema[format-nongpl]>=4.23.0",
-  "referencing>=0.35.0,<0.37.0",
+  "referencing>=0.35.0,<0.38.0",
   # ArtifactIntegrity.v1 Ed25519 sign/verify (docs/trust-model.md)
   "PyNaCl>=1.5.0,<2",
 ]
@@ -31,7 +31,7 @@ quality = [
 # verifier OCI image or a PCS_BUILD_VERIFIER=1 wheel (see docs/distribution.md).
 verifier = [
   "jsonschema[format-nongpl]>=4.23.0",
-  "referencing>=0.35.0,<0.37.0",
+  "referencing>=0.35.0,<0.38.0",
 ]
 
 [project.scripts]