diff --git a/net-im/synapse/synapse-1.93.0.ebuild b/net-im/synapse/synapse-1.93.0-r1.ebuild
similarity index 97%
rename from net-im/synapse/synapse-1.93.0.ebuild
rename to net-im/synapse/synapse-1.93.0-r1.ebuild
index 931fb634d2a4d..efc6e857ff1b7 100644
--- a/net-im/synapse/synapse-1.93.0.ebuild
+++ b/net-im/synapse/synapse-1.93.0-r1.ebuild
@@ -94,6 +94,7 @@ DEPEND="
 	acct-group/synapse
 "
 # <pydantic-2, see https://github.com/matrix-org/synapse/issues/15858
+# >twisted-23.8 breaks tests, see https://github.com/matrix-org/synapse/pull/16528
 RDEPEND="
 	${DEPEND}
 	dev-python/attrs[${PYTHON_USEDEP}]
@@ -122,7 +123,7 @@ RDEPEND="
 	dev-python/signedjson[${PYTHON_USEDEP}]
 	dev-python/sortedcontainers[${PYTHON_USEDEP}]
 	dev-python/treq[${PYTHON_USEDEP}]
-	dev-python/twisted[${PYTHON_USEDEP}]
+	<dev-python/twisted-23.8.1[${PYTHON_USEDEP}]
 	dev-python/typing-extensions[${PYTHON_USEDEP}]
 	dev-python/unpaddedbase64[${PYTHON_USEDEP}]
 	postgres? ( dev-python/psycopg:2[${PYTHON_USEDEP}] )
diff --git a/net-im/synapse/synapse-1.95.0.ebuild b/net-im/synapse/synapse-1.95.0-r1.ebuild
similarity index 97%
rename from net-im/synapse/synapse-1.95.0.ebuild
rename to net-im/synapse/synapse-1.95.0-r1.ebuild
index 853662c0778a3..c28f39b29d11c 100644
--- a/net-im/synapse/synapse-1.95.0.ebuild
+++ b/net-im/synapse/synapse-1.95.0-r1.ebuild
@@ -93,6 +93,7 @@ DEPEND="
 	acct-user/synapse
 	acct-group/synapse
 "
+# >twisted-23.8 breaks tests, see https://github.com/matrix-org/synapse/pull/16528
 RDEPEND="
 	${DEPEND}
 	dev-python/attrs[${PYTHON_USEDEP}]
@@ -121,7 +122,7 @@ RDEPEND="
 	dev-python/signedjson[${PYTHON_USEDEP}]
 	dev-python/sortedcontainers[${PYTHON_USEDEP}]
 	dev-python/treq[${PYTHON_USEDEP}]
-	dev-python/twisted[${PYTHON_USEDEP}]
+	<dev-python/twisted-23.8.1[${PYTHON_USEDEP}]
 	dev-python/typing-extensions[${PYTHON_USEDEP}]
 	dev-python/unpaddedbase64[${PYTHON_USEDEP}]
 	postgres? ( dev-python/psycopg:2[${PYTHON_USEDEP}] )