diff --git a/poetry.lock b/poetry.lock
index e62c10da9f..dd2031cc77 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -2427,13 +2427,13 @@ tornado = ["tornado (>=5)"]
 
 [[package]]
 name = "service-identity"
-version = "23.1.0"
+version = "21.1.0"
 description = "Service identity verification for pyOpenSSL & cryptography."
 optional = false
-python-versions = ">=3.8"
+python-versions = "*"
 files = [
-    {file = "service_identity-23.1.0-py3-none-any.whl", hash = "sha256:87415a691d52fcad954a500cb81f424d0273f8e7e3ee7d766128f4575080f383"},
-    {file = "service_identity-23.1.0.tar.gz", hash = "sha256:ecb33cd96307755041e978ab14f8b14e13b40f1fbd525a4dc78f46d2b986431d"},
+    {file = "service-identity-21.1.0.tar.gz", hash = "sha256:6e6c6086ca271dc11b033d17c3a8bea9f24ebff920c587da090afc9519419d34"},
+    {file = "service_identity-21.1.0-py2.py3-none-any.whl", hash = "sha256:f0b0caac3d40627c3c04d7a51b6e06721857a0e10a8775f2d1d7e72901b3a7db"},
 ]
 
 [package.dependencies]
diff --git a/pyproject.toml b/pyproject.toml
index 0585a9b01e..3539b9a7e5 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -163,7 +163,7 @@ canonicaljson = "^2.0.0"
 # we use the type definitions added in signedjson 1.1.
 signedjson = "^1.1.0"
 # validating SSL certs for IP addresses requires service_identity 18.1.
-service-identity = ">=18.1.0"
+service-identity = ">=18.1.0,<23.0.0"
 # Twisted 18.9 introduces some logger improvements that the structured
 # logger utilises
 Twisted = {extras = ["tls"], version = ">=18.9.0"}