1 files changed, 4 insertions, 4 deletions
diff --git a/synapse/python_dependencies.py b/synapse/python_dependencies.py
index 0f339a0320..2947f37f1a 100644
--- a/synapse/python_dependencies.py
+++ b/synapse/python_dependencies.py
@@ -58,7 +58,10 @@ REQUIREMENTS = {
     "msgpack-python>=0.3.0": ["msgpack"],
     "phonenumbers>=8.2.0": ["phonenumbers"],
     "six>=1.10": ["six"],
-    "prometheus_client>=0.0.18": ["prometheus_client"],
+
+    # prometheus_client 0.4.0 changed the format of counter metrics
+    # (cf https://github.com/matrix-org/synapse/issues/4001)
+    "prometheus_client>=0.0.18,<0.4.0": ["prometheus_client"],
 
     # we use attr.s(slots), which arrived in 16.0.0
     "attrs>=16.0.0": ["attr>=16.0.0"],
@@ -79,9 +82,6 @@ CONDITIONAL_REQUIREMENTS = {
     "psutil": {
         "psutil>=2.0.0": ["psutil>=2.0.0"],
     },
-    "affinity": {
-        "affinity": ["affinity"],
-    },
     "postgres": {
         "psycopg2>=2.6": ["psycopg2"]
     }